SF: Adding Mock Display and tests for RefreshRateStats.

Following ag/6005545.

Test: adding SF tests.
Bug: 113612090
Change-Id: Ic4d1ca622f00c4396ae19c44defac0c69fabed1d
diff --git a/services/surfaceflinger/DisplayHardware/HWC2.cpp b/services/surfaceflinger/DisplayHardware/HWC2.cpp
index 392b608..68e7876 100644
--- a/services/surfaceflinger/DisplayHardware/HWC2.cpp
+++ b/services/surfaceflinger/DisplayHardware/HWC2.cpp
@@ -143,8 +143,8 @@
         return error;
     }
 
-    auto display = std::make_unique<Display>(
-            *mComposer.get(), mPowerAdvisor, mCapabilities, displayId, DisplayType::Virtual);
+    auto display = std::make_unique<impl::Display>(*mComposer.get(), mPowerAdvisor, mCapabilities,
+                                                   displayId, DisplayType::Virtual);
     display->setConnected(true);
     *outDisplay = display.get();
     mDisplays.emplace(displayId, std::move(display));
@@ -182,8 +182,8 @@
             return;
         }
 
-        auto newDisplay = std::make_unique<Display>(
-                *mComposer.get(), mPowerAdvisor, mCapabilities, displayId, displayType);
+        auto newDisplay = std::make_unique<impl::Display>(*mComposer.get(), mPowerAdvisor,
+                                                          mCapabilities, displayId, displayType);
         newDisplay->setConnected(true);
         mDisplays.emplace(displayId, std::move(newDisplay));
     } else if (connection == Connection::Disconnected) {
@@ -224,7 +224,36 @@
 }
 
 // Display methods
+Display::~Display() = default;
 
+Display::Config::Config(Display& display, hwc2_config_t id)
+      : mDisplay(display),
+        mId(id),
+        mWidth(-1),
+        mHeight(-1),
+        mVsyncPeriod(-1),
+        mDpiX(-1),
+        mDpiY(-1) {}
+
+Display::Config::Builder::Builder(Display& display, hwc2_config_t id)
+      : mConfig(new Config(display, id)) {}
+
+float Display::Config::Builder::getDefaultDensity() {
+    // Default density is based on TVs: 1080p displays get XHIGH density, lower-
+    // resolution displays get TV density. Maybe eventually we'll need to update
+    // it for 4k displays, though hopefully those will just report accurate DPI
+    // information to begin with. This is also used for virtual displays and
+    // older HWC implementations, so be careful about orientation.
+
+    auto longDimension = std::max(mConfig->mWidth, mConfig->mHeight);
+    if (longDimension >= 1080) {
+        return ACONFIGURATION_DENSITY_XHIGH;
+    } else {
+        return ACONFIGURATION_DENSITY_TV;
+    }
+}
+
+namespace impl {
 Display::Display(android::Hwc2::Composer& composer, android::Hwc2::PowerAdvisor& advisor,
                  const std::unordered_set<Capability>& capabilities, hwc2_display_t id,
                  DisplayType type)
@@ -272,35 +301,7 @@
     }
 }
 
-Display::Config::Config(Display& display, hwc2_config_t id)
-  : mDisplay(display),
-    mId(id),
-    mWidth(-1),
-    mHeight(-1),
-    mVsyncPeriod(-1),
-    mDpiX(-1),
-    mDpiY(-1) {}
-
-Display::Config::Builder::Builder(Display& display, hwc2_config_t id)
-  : mConfig(new Config(display, id)) {}
-
-float Display::Config::Builder::getDefaultDensity() {
-    // Default density is based on TVs: 1080p displays get XHIGH density, lower-
-    // resolution displays get TV density. Maybe eventually we'll need to update
-    // it for 4k displays, though hopefully those will just report accurate DPI
-    // information to begin with. This is also used for virtual displays and
-    // older HWC implementations, so be careful about orientation.
-
-    auto longDimension = std::max(mConfig->mWidth, mConfig->mHeight);
-    if (longDimension >= 1080) {
-        return ACONFIGURATION_DENSITY_XHIGH;
-    } else {
-        return ACONFIGURATION_DENSITY_TV;
-    }
-}
-
 // Required by HWC2 display
-
 Error Display::acceptChanges()
 {
     auto intError = mComposer.acceptDisplayChanges(mId);
@@ -794,6 +795,7 @@
 
     return mLayers.at(id).get();
 }
+} // namespace impl
 
 // Layer methods
 
diff --git a/services/surfaceflinger/DisplayHardware/HWC2.h b/services/surfaceflinger/DisplayHardware/HWC2.h
index f5cb97e..c1f481a 100644
--- a/services/surfaceflinger/DisplayHardware/HWC2.h
+++ b/services/surfaceflinger/DisplayHardware/HWC2.h
@@ -130,16 +130,11 @@
 };
 
 // Convenience C++ class to access hwc2_device_t Display functions directly.
-class Display
-{
+class Display {
 public:
-    Display(android::Hwc2::Composer& composer, android::Hwc2::PowerAdvisor& advisor,
-            const std::unordered_set<Capability>& capabilities,
-            hwc2_display_t id, DisplayType type);
-    ~Display();
+    virtual ~Display();
 
-    class Config
-    {
+    class Config {
     public:
         class Builder
         {
@@ -207,78 +202,136 @@
         float mDpiY;
     };
 
-    // Required by HWC2
+    virtual hwc2_display_t getId() const = 0;
+    virtual bool isConnected() const = 0;
+    virtual void setConnected(bool connected) = 0; // For use by Device only
+    virtual const std::unordered_set<DisplayCapability>& getCapabilities() const = 0;
 
-    [[clang::warn_unused_result]] Error acceptChanges();
-    [[clang::warn_unused_result]] Error createLayer(Layer** outLayer);
-    [[clang::warn_unused_result]] Error destroyLayer(Layer* layer);
-    [[clang::warn_unused_result]] Error getActiveConfig(
-            std::shared_ptr<const Config>* outConfig) const;
-    [[clang::warn_unused_result]] Error getActiveConfigIndex(int* outIndex) const;
-    [[clang::warn_unused_result]] Error getChangedCompositionTypes(
-            std::unordered_map<Layer*, Composition>* outTypes);
-    [[clang::warn_unused_result]] Error getColorModes(
-            std::vector<android::ui::ColorMode>* outModes) const;
+    [[clang::warn_unused_result]] virtual Error acceptChanges() = 0;
+    [[clang::warn_unused_result]] virtual Error createLayer(Layer** outLayer) = 0;
+    [[clang::warn_unused_result]] virtual Error destroyLayer(Layer* layer) = 0;
+    [[clang::warn_unused_result]] virtual Error getActiveConfig(
+            std::shared_ptr<const Config>* outConfig) const = 0;
+    [[clang::warn_unused_result]] virtual Error getActiveConfigIndex(int* outIndex) const = 0;
+    [[clang::warn_unused_result]] virtual Error getChangedCompositionTypes(
+            std::unordered_map<Layer*, Composition>* outTypes) = 0;
+    [[clang::warn_unused_result]] virtual Error getColorModes(
+            std::vector<android::ui::ColorMode>* outModes) const = 0;
     // Returns a bitmask which contains HdrMetadata::Type::*.
-    [[clang::warn_unused_result]] int32_t getSupportedPerFrameMetadata() const;
-    [[clang::warn_unused_result]] Error getRenderIntents(
+    [[clang::warn_unused_result]] virtual int32_t getSupportedPerFrameMetadata() const = 0;
+    [[clang::warn_unused_result]] virtual Error getRenderIntents(
             android::ui::ColorMode colorMode,
-            std::vector<android::ui::RenderIntent>* outRenderIntents) const;
-    [[clang::warn_unused_result]] Error getDataspaceSaturationMatrix(
-            android::ui::Dataspace dataspace, android::mat4* outMatrix);
+            std::vector<android::ui::RenderIntent>* outRenderIntents) const = 0;
+    [[clang::warn_unused_result]] virtual Error getDataspaceSaturationMatrix(
+            android::ui::Dataspace dataspace, android::mat4* outMatrix) = 0;
+
+    // Doesn't call into the HWC2 device, so no Errors are possible
+    virtual std::vector<std::shared_ptr<const Config>> getConfigs() const = 0;
+
+    [[clang::warn_unused_result]] virtual Error getName(std::string* outName) const = 0;
+    [[clang::warn_unused_result]] virtual Error getRequests(
+            DisplayRequest* outDisplayRequests,
+            std::unordered_map<Layer*, LayerRequest>* outLayerRequests) = 0;
+    [[clang::warn_unused_result]] virtual Error getType(DisplayType* outType) const = 0;
+    [[clang::warn_unused_result]] virtual Error supportsDoze(bool* outSupport) const = 0;
+    [[clang::warn_unused_result]] virtual Error getHdrCapabilities(
+            android::HdrCapabilities* outCapabilities) const = 0;
+    [[clang::warn_unused_result]] virtual Error getDisplayedContentSamplingAttributes(
+            android::ui::PixelFormat* outFormat, android::ui::Dataspace* outDataspace,
+            uint8_t* outComponentMask) const = 0;
+    [[clang::warn_unused_result]] virtual Error setDisplayContentSamplingEnabled(
+            bool enabled, uint8_t componentMask, uint64_t maxFrames) const = 0;
+    [[clang::warn_unused_result]] virtual Error getDisplayedContentSample(
+            uint64_t maxFrames, uint64_t timestamp,
+            android::DisplayedFrameStats* outStats) const = 0;
+    [[clang::warn_unused_result]] virtual Error getReleaseFences(
+            std::unordered_map<Layer*, android::sp<android::Fence>>* outFences) const = 0;
+    [[clang::warn_unused_result]] virtual Error present(
+            android::sp<android::Fence>* outPresentFence) = 0;
+    [[clang::warn_unused_result]] virtual Error setActiveConfig(
+            const std::shared_ptr<const Config>& config) = 0;
+    [[clang::warn_unused_result]] virtual Error setClientTarget(
+            uint32_t slot, const android::sp<android::GraphicBuffer>& target,
+            const android::sp<android::Fence>& acquireFence, android::ui::Dataspace dataspace) = 0;
+    [[clang::warn_unused_result]] virtual Error setColorMode(
+            android::ui::ColorMode mode, android::ui::RenderIntent renderIntent) = 0;
+    [[clang::warn_unused_result]] virtual Error setColorTransform(
+            const android::mat4& matrix, android_color_transform_t hint) = 0;
+    [[clang::warn_unused_result]] virtual Error setOutputBuffer(
+            const android::sp<android::GraphicBuffer>& buffer,
+            const android::sp<android::Fence>& releaseFence) = 0;
+    [[clang::warn_unused_result]] virtual Error setPowerMode(PowerMode mode) = 0;
+    [[clang::warn_unused_result]] virtual Error setVsyncEnabled(Vsync enabled) = 0;
+    [[clang::warn_unused_result]] virtual Error validate(uint32_t* outNumTypes,
+                                                         uint32_t* outNumRequests) = 0;
+    [[clang::warn_unused_result]] virtual Error presentOrValidate(
+            uint32_t* outNumTypes, uint32_t* outNumRequests,
+            android::sp<android::Fence>* outPresentFence, uint32_t* state) = 0;
+};
+
+namespace impl {
+
+class Display : public HWC2::Display {
+public:
+    Display(android::Hwc2::Composer& composer, android::Hwc2::PowerAdvisor& advisor,
+            const std::unordered_set<Capability>& capabilities, hwc2_display_t id,
+            DisplayType type);
+    ~Display() override;
+
+    // Required by HWC2
+    Error acceptChanges() override;
+    Error createLayer(Layer** outLayer) override;
+    Error destroyLayer(Layer* layer) override;
+    Error getActiveConfig(std::shared_ptr<const Config>* outConfig) const override;
+    Error getActiveConfigIndex(int* outIndex) const override;
+    Error getChangedCompositionTypes(std::unordered_map<Layer*, Composition>* outTypes) override;
+    Error getColorModes(std::vector<android::ui::ColorMode>* outModes) const override;
+    // Returns a bitmask which contains HdrMetadata::Type::*.
+    int32_t getSupportedPerFrameMetadata() const override;
+    Error getRenderIntents(android::ui::ColorMode colorMode,
+                           std::vector<android::ui::RenderIntent>* outRenderIntents) const override;
+    Error getDataspaceSaturationMatrix(android::ui::Dataspace dataspace,
+                                       android::mat4* outMatrix) override;
 
     // Doesn't call into the HWC2 device, so no errors are possible
-    std::vector<std::shared_ptr<const Config>> getConfigs() const;
+    std::vector<std::shared_ptr<const Config>> getConfigs() const override;
 
-    [[clang::warn_unused_result]] Error getName(std::string* outName) const;
-    [[clang::warn_unused_result]] Error getRequests(
-            DisplayRequest* outDisplayRequests,
-            std::unordered_map<Layer*, LayerRequest>* outLayerRequests);
-    [[clang::warn_unused_result]] Error getType(DisplayType* outType) const;
-    [[clang::warn_unused_result]] Error supportsDoze(bool* outSupport) const;
-    [[clang::warn_unused_result]] Error getHdrCapabilities(
-            android::HdrCapabilities* outCapabilities) const;
-    [[clang::warn_unused_result]] Error getDisplayedContentSamplingAttributes(
-            android::ui::PixelFormat* outFormat, android::ui::Dataspace* outDataspace,
-            uint8_t* outComponentMask) const;
-    [[clang::warn_unused_result]] Error setDisplayContentSamplingEnabled(bool enabled,
-                                                                         uint8_t componentMask,
-                                                                         uint64_t maxFrames) const;
-    [[clang::warn_unused_result]] Error getDisplayedContentSample(
-            uint64_t maxFrames, uint64_t timestamp, android::DisplayedFrameStats* outStats) const;
-    [[clang::warn_unused_result]] Error getReleaseFences(
-            std::unordered_map<Layer*,
-                    android::sp<android::Fence>>* outFences) const;
-    [[clang::warn_unused_result]] Error present(
-            android::sp<android::Fence>* outPresentFence);
-    [[clang::warn_unused_result]] Error setActiveConfig(
-            const std::shared_ptr<const Config>& config);
-    [[clang::warn_unused_result]] Error setClientTarget(
-            uint32_t slot, const android::sp<android::GraphicBuffer>& target,
-            const android::sp<android::Fence>& acquireFence,
-            android::ui::Dataspace dataspace);
-    [[clang::warn_unused_result]] Error setColorMode(
-            android::ui::ColorMode mode,
-            android::ui::RenderIntent renderIntent);
-    [[clang::warn_unused_result]] Error setColorTransform(
-            const android::mat4& matrix, android_color_transform_t hint);
-    [[clang::warn_unused_result]] Error setOutputBuffer(
-            const android::sp<android::GraphicBuffer>& buffer,
-            const android::sp<android::Fence>& releaseFence);
-    [[clang::warn_unused_result]] Error setPowerMode(PowerMode mode);
-    [[clang::warn_unused_result]] Error setVsyncEnabled(Vsync enabled);
-    [[clang::warn_unused_result]] Error validate(uint32_t* outNumTypes,
-            uint32_t* outNumRequests);
-    [[clang::warn_unused_result]] Error presentOrValidate(uint32_t* outNumTypes,
-            uint32_t* outNumRequests,
-            android::sp<android::Fence>* outPresentFence, uint32_t* state);
+    Error getName(std::string* outName) const override;
+    Error getRequests(DisplayRequest* outDisplayRequests,
+                      std::unordered_map<Layer*, LayerRequest>* outLayerRequests) override;
+    Error getType(DisplayType* outType) const override;
+    Error supportsDoze(bool* outSupport) const override;
+    Error getHdrCapabilities(android::HdrCapabilities* outCapabilities) const override;
+    Error getDisplayedContentSamplingAttributes(android::ui::PixelFormat* outFormat,
+                                                android::ui::Dataspace* outDataspace,
+                                                uint8_t* outComponentMask) const override;
+    Error setDisplayContentSamplingEnabled(bool enabled, uint8_t componentMask,
+                                           uint64_t maxFrames) const override;
+    Error getDisplayedContentSample(uint64_t maxFrames, uint64_t timestamp,
+                                    android::DisplayedFrameStats* outStats) const override;
+    Error getReleaseFences(
+            std::unordered_map<Layer*, android::sp<android::Fence>>* outFences) const override;
+    Error present(android::sp<android::Fence>* outPresentFence) override;
+    Error setActiveConfig(const std::shared_ptr<const HWC2::Display::Config>& config) override;
+    Error setClientTarget(uint32_t slot, const android::sp<android::GraphicBuffer>& target,
+                          const android::sp<android::Fence>& acquireFence,
+                          android::ui::Dataspace dataspace) override;
+    Error setColorMode(android::ui::ColorMode mode,
+                       android::ui::RenderIntent renderIntent) override;
+    Error setColorTransform(const android::mat4& matrix, android_color_transform_t hint) override;
+    Error setOutputBuffer(const android::sp<android::GraphicBuffer>& buffer,
+                          const android::sp<android::Fence>& releaseFence) override;
+    Error setPowerMode(PowerMode mode) override;
+    Error setVsyncEnabled(Vsync enabled) override;
+    Error validate(uint32_t* outNumTypes, uint32_t* outNumRequests) override;
+    Error presentOrValidate(uint32_t* outNumTypes, uint32_t* outNumRequests,
+                            android::sp<android::Fence>* outPresentFence, uint32_t* state) override;
 
     // Other Display methods
-
-    hwc2_display_t getId() const { return mId; }
-    bool isConnected() const { return mIsConnected; }
-    void setConnected(bool connected);  // For use by Device only
-    const std::unordered_set<DisplayCapability>& getCapabilities() const {
+    hwc2_display_t getId() const override { return mId; }
+    bool isConnected() const override { return mIsConnected; }
+    void setConnected(bool connected) override; // For use by Device only
+    const std::unordered_set<DisplayCapability>& getCapabilities() const override {
         return mDisplayCapabilities;
     };
 
@@ -309,6 +362,7 @@
     std::unordered_map<hwc2_config_t, std::shared_ptr<const Config>> mConfigs;
     std::unordered_set<DisplayCapability> mDisplayCapabilities;
 };
+} // namespace impl
 
 // Convenience C++ class to access hwc2_device_t Layer functions directly.
 class Layer
diff --git a/services/surfaceflinger/Scheduler/RefreshRateConfigs.h b/services/surfaceflinger/Scheduler/RefreshRateConfigs.h
index ce1637a..bfe5da5 100644
--- a/services/surfaceflinger/Scheduler/RefreshRateConfigs.h
+++ b/services/surfaceflinger/Scheduler/RefreshRateConfigs.h
@@ -19,9 +19,11 @@
 #include <algorithm>
 #include <numeric>
 
-#include "Scheduler/SchedulerUtils.h"
 #include "android-base/stringprintf.h"
 
+#include "DisplayHardware/HWComposer.h"
+#include "Scheduler/SchedulerUtils.h"
+
 namespace android {
 namespace scheduler {
 
@@ -51,57 +53,58 @@
     // baking them in.
     explicit RefreshRateConfigs(
             const std::vector<std::shared_ptr<const HWC2::Display::Config>>& configs) {
-        // This is the rate that HWC encapsulates right now when the screen is off.
-        RefreshRate rate;
-        rate.type = RefreshRateType::POWER_SAVING;
-        rate.configId = SCREEN_OFF_CONFIG_ID;
-        rate.name = "ScreenOff";
-        mRefreshRates.push_back(rate);
-
-        if (configs.size() < 1) {
-            return;
-        }
-
-        std::vector<std::pair<int, nsecs_t>> configIdToVsyncPeriod;
-        for (int i = 0; i < configs.size(); ++i) {
-            configIdToVsyncPeriod.push_back(std::make_pair(i, configs.at(i)->getVsyncPeriod()));
-        }
-        std::sort(configIdToVsyncPeriod.begin(), configIdToVsyncPeriod.end(),
-                  [](const std::pair<int, nsecs_t>& a, const std::pair<int, nsecs_t>& b) {
-                      return a.second > b.second;
-                  });
-
-        nsecs_t vsyncPeriod = configIdToVsyncPeriod.at(0).second;
-        if (vsyncPeriod != 0) {
-            const float fps = std::chrono::nanoseconds(1).count() / vsyncPeriod;
-            rate.type = RefreshRateType::DEFAULT;
-            rate.configId = configIdToVsyncPeriod.at(0).first;
-            rate.name = base::StringPrintf("%2.ffps", fps);
-            mRefreshRates.push_back(rate);
-        }
-        if (configs.size() < 2) {
-            return;
-        }
-
-        vsyncPeriod = configIdToVsyncPeriod.at(1).second;
-        if (vsyncPeriod != 0) {
-            const float fps = std::chrono::nanoseconds(1).count() / vsyncPeriod;
-            rate.type = RefreshRateType::PERFORMANCE;
-            rate.configId = configIdToVsyncPeriod.at(1).first;
-            rate.name = base::StringPrintf("%2.ffps", fps);
-            mRefreshRates.push_back(rate);
-        }
-
-        for (auto refreshRate : mRefreshRates) {
-            ALOGV("type: %d, id: %d, name: %s", refreshRate.type, refreshRate.configId,
-                  refreshRate.name.c_str());
-        }
+        init(configs);
     }
     ~RefreshRateConfigs() = default;
 
     const std::vector<RefreshRate>& getRefreshRates() { return mRefreshRates; }
 
 private:
+    void init(const std::vector<std::shared_ptr<const HWC2::Display::Config>>& configs) {
+        // This is the rate that HWC encapsulates right now when the device is in DOZE mode.
+        mRefreshRates.push_back(
+                RefreshRate{RefreshRateType::POWER_SAVING, SCREEN_OFF_CONFIG_ID, "ScreenOff"});
+
+        if (configs.size() < 1) {
+            ALOGE("Device does not have valid configs. Config size is 0.");
+            return;
+        }
+
+        // Create a map between config index and vsync period. This is all the info we need
+        // from the configs.
+        std::vector<std::pair<int, nsecs_t>> configIdToVsyncPeriod;
+        for (int i = 0; i < configs.size(); ++i) {
+            configIdToVsyncPeriod.emplace_back(i, configs.at(i)->getVsyncPeriod());
+        }
+
+        std::sort(configIdToVsyncPeriod.begin(), configIdToVsyncPeriod.end(),
+                  [](const std::pair<int, nsecs_t>& a, const std::pair<int, nsecs_t>& b) {
+                      return a.second > b.second;
+                  });
+
+        // When the configs are ordered by the resync rate. We assume that the first one is DEFAULT.
+        nsecs_t vsyncPeriod = configIdToVsyncPeriod[0].second;
+        if (vsyncPeriod != 0) {
+            const float fps = 1e9 / vsyncPeriod;
+            mRefreshRates.push_back(RefreshRate{RefreshRateType::DEFAULT,
+                                                configIdToVsyncPeriod[0].first,
+                                                base::StringPrintf("%2.ffps", fps)});
+        }
+        if (configs.size() < 2) {
+            return;
+        }
+
+        // When the configs are ordered by the resync rate. We assume that the second one is
+        // PERFORMANCE, eg. the higher rate.
+        vsyncPeriod = configIdToVsyncPeriod[1].second;
+        if (vsyncPeriod != 0) {
+            const float fps = 1e9 / vsyncPeriod;
+            mRefreshRates.push_back(RefreshRate{RefreshRateType::PERFORMANCE,
+                                                configIdToVsyncPeriod[1].first,
+                                                base::StringPrintf("%2.ffps", fps)});
+        }
+    }
+
     std::vector<RefreshRate> mRefreshRates;
 };
 
diff --git a/services/surfaceflinger/Scheduler/RefreshRateStats.h b/services/surfaceflinger/Scheduler/RefreshRateStats.h
index cd81e4d..7e22232 100644
--- a/services/surfaceflinger/Scheduler/RefreshRateStats.h
+++ b/services/surfaceflinger/Scheduler/RefreshRateStats.h
@@ -82,9 +82,11 @@
 
         std::unordered_map<std::string, int64_t> totalTime;
         for (auto config : mRefreshRateConfigs->getRefreshRates()) {
+            int64_t totalTimeForConfig = 0;
             if (mConfigModesTotalTime.find(config.configId) != mConfigModesTotalTime.end()) {
-                totalTime[config.name] = mConfigModesTotalTime.at(config.configId);
+                totalTimeForConfig = mConfigModesTotalTime.at(config.configId);
             }
+            totalTime[config.name] = totalTimeForConfig;
         }
         return totalTime;
     }
diff --git a/services/surfaceflinger/SurfaceFlinger.cpp b/services/surfaceflinger/SurfaceFlinger.cpp
index 8746a68..e298e20 100644
--- a/services/surfaceflinger/SurfaceFlinger.cpp
+++ b/services/surfaceflinger/SurfaceFlinger.cpp
@@ -4338,7 +4338,7 @@
 
     if (display->isPrimary()) {
         mTimeStats->setPowerMode(mode);
-        if (mUseScheduler) {
+        if (mUseScheduler && mRefreshRateStats) {
             // Update refresh rate stats.
             mRefreshRateStats->setPowerMode(mode);
         }
diff --git a/services/surfaceflinger/tests/unittests/Android.bp b/services/surfaceflinger/tests/unittests/Android.bp
index ad31a40..e34e568 100644
--- a/services/surfaceflinger/tests/unittests/Android.bp
+++ b/services/surfaceflinger/tests/unittests/Android.bp
@@ -44,8 +44,10 @@
         "LayerHistoryTest.cpp",
         "SchedulerTest.cpp",
         "SchedulerUtilsTest.cpp",
+        "RefreshRateStatsTest.cpp",
         "TimeStatsTest.cpp",
         "mock/DisplayHardware/MockComposer.cpp",
+        "mock/DisplayHardware/MockDisplay.cpp",
         "mock/DisplayHardware/MockPowerAdvisor.cpp",
         "mock/gui/MockGraphicBufferConsumer.cpp",
         "mock/gui/MockGraphicBufferProducer.cpp",
diff --git a/services/surfaceflinger/tests/unittests/RefreshRateStatsTest.cpp b/services/surfaceflinger/tests/unittests/RefreshRateStatsTest.cpp
new file mode 100644
index 0000000..0384d9d
--- /dev/null
+++ b/services/surfaceflinger/tests/unittests/RefreshRateStatsTest.cpp
@@ -0,0 +1,212 @@
+/*
+ * Copyright 2019 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#undef LOG_TAG
+#define LOG_TAG "SchedulerUnittests"
+
+#include <gmock/gmock.h>
+#include <log/log.h>
+#include <thread>
+
+#include "Scheduler/RefreshRateStats.h"
+#include "mock/DisplayHardware/MockDisplay.h"
+
+using namespace std::chrono_literals;
+
+namespace android {
+namespace scheduler {
+
+class RefreshRateStatsTest : public testing::Test {
+protected:
+    static constexpr int CONFIG_ID_90 = 0;
+    static constexpr int CONFIG_ID_60 = 1;
+    static constexpr int64_t VSYNC_90 = 11111111;
+    static constexpr int64_t VSYNC_60 = 16666667;
+
+    RefreshRateStatsTest();
+    ~RefreshRateStatsTest();
+
+    void init(std::vector<std::shared_ptr<const HWC2::Display::Config>> configs);
+
+    std::unique_ptr<RefreshRateStats> mRefreshRateStats;
+};
+
+RefreshRateStatsTest::RefreshRateStatsTest() {
+    const ::testing::TestInfo* const test_info =
+            ::testing::UnitTest::GetInstance()->current_test_info();
+    ALOGD("**** Setting up for %s.%s\n", test_info->test_case_name(), test_info->name());
+}
+
+RefreshRateStatsTest::~RefreshRateStatsTest() {
+    const ::testing::TestInfo* const test_info =
+            ::testing::UnitTest::GetInstance()->current_test_info();
+    ALOGD("**** Tearing down after %s.%s\n", test_info->test_case_name(), test_info->name());
+}
+
+void RefreshRateStatsTest::init(std::vector<std::shared_ptr<const HWC2::Display::Config>> configs) {
+    mRefreshRateStats = std::make_unique<RefreshRateStats>(configs);
+}
+
+namespace {
+/* ------------------------------------------------------------------------
+ * Test cases
+ */
+TEST_F(RefreshRateStatsTest, canCreateAndDestroyTest) {
+    std::vector<std::shared_ptr<const HWC2::Display::Config>> configs;
+    init(configs);
+
+    // There is one default config, so the refresh rates should have one item.
+    ASSERT_EQ(1, mRefreshRateStats->getTotalTimes().size());
+}
+
+TEST_F(RefreshRateStatsTest, oneConfigTest) {
+    auto display = new Hwc2::mock::Display();
+
+    auto config = HWC2::Display::Config::Builder(*display, CONFIG_ID_90);
+    config.setVsyncPeriod(VSYNC_90);
+    std::vector<std::shared_ptr<const HWC2::Display::Config>> configs;
+    configs.push_back(config.build());
+
+    init(configs);
+
+    std::unordered_map<std::string, int64_t> times = mRefreshRateStats->getTotalTimes();
+    ASSERT_EQ(2, times.size());
+    ASSERT_EQ(0, times["ScreenOff"]);
+    ASSERT_EQ(0, times["90fps"]);
+    // Setting up tests on mobile harness can be flaky with time passing, so testing for
+    // exact time changes can result in flaxy numbers. To avoid that remember old
+    // numbers to make sure the correct values are increasing in the next test.
+    int screenOff = times["ScreenOff"];
+    int ninety = times["90fps"];
+
+    // Screen is off by default.
+    std::this_thread::sleep_for(std::chrono::milliseconds(2));
+    times = mRefreshRateStats->getTotalTimes();
+    ASSERT_LT(screenOff, times["ScreenOff"]);
+    ASSERT_EQ(0, times["90fps"]);
+    screenOff = times["ScreenOff"];
+
+    mRefreshRateStats->setPowerMode(HWC_POWER_MODE_NORMAL);
+    std::this_thread::sleep_for(std::chrono::milliseconds(2));
+    times = mRefreshRateStats->getTotalTimes();
+    ASSERT_EQ(screenOff, times["ScreenOff"]);
+    ASSERT_LT(ninety, times["90fps"]);
+    ninety = times["90fps"];
+
+    mRefreshRateStats->setPowerMode(HWC_POWER_MODE_DOZE);
+    std::this_thread::sleep_for(std::chrono::milliseconds(2));
+    times = mRefreshRateStats->getTotalTimes();
+    ASSERT_LT(screenOff, times["ScreenOff"]);
+    ASSERT_EQ(ninety, times["90fps"]);
+    screenOff = times["ScreenOff"];
+
+    mRefreshRateStats->setConfigMode(CONFIG_ID_90);
+    std::this_thread::sleep_for(std::chrono::milliseconds(2));
+    times = mRefreshRateStats->getTotalTimes();
+    // Because the power mode is not HWC_POWER_MODE_NORMAL, switching the config
+    // does not update refresh rates that come from the config.
+    ASSERT_LT(screenOff, times["ScreenOff"]);
+    ASSERT_EQ(ninety, times["90fps"]);
+}
+
+TEST_F(RefreshRateStatsTest, twoConfigsTest) {
+    auto display = new Hwc2::mock::Display();
+
+    auto config90 = HWC2::Display::Config::Builder(*display, CONFIG_ID_90);
+    config90.setVsyncPeriod(VSYNC_90);
+    std::vector<std::shared_ptr<const HWC2::Display::Config>> configs;
+    configs.push_back(config90.build());
+
+    auto config60 = HWC2::Display::Config::Builder(*display, CONFIG_ID_60);
+    config60.setVsyncPeriod(VSYNC_60);
+    configs.push_back(config60.build());
+
+    init(configs);
+
+    std::unordered_map<std::string, int64_t> times = mRefreshRateStats->getTotalTimes();
+    ASSERT_EQ(3, times.size());
+    ASSERT_EQ(0, times["ScreenOff"]);
+    ASSERT_EQ(0, times["60fps"]);
+    ASSERT_EQ(0, times["90fps"]);
+    // Setting up tests on mobile harness can be flaky with time passing, so testing for
+    // exact time changes can result in flaxy numbers. To avoid that remember old
+    // numbers to make sure the correct values are increasing in the next test.
+    int screenOff = times["ScreenOff"];
+    int sixty = times["60fps"];
+    int ninety = times["90fps"];
+
+    // Screen is off by default.
+    std::this_thread::sleep_for(std::chrono::milliseconds(2));
+    times = mRefreshRateStats->getTotalTimes();
+    ASSERT_LT(screenOff, times["ScreenOff"]);
+    ASSERT_EQ(sixty, times["60fps"]);
+    ASSERT_EQ(ninety, times["90fps"]);
+    screenOff = times["ScreenOff"];
+
+    mRefreshRateStats->setPowerMode(HWC_POWER_MODE_NORMAL);
+    std::this_thread::sleep_for(std::chrono::milliseconds(2));
+    times = mRefreshRateStats->getTotalTimes();
+    ASSERT_EQ(screenOff, times["ScreenOff"]);
+    ASSERT_EQ(sixty, times["60fps"]);
+    ASSERT_LT(ninety, times["90fps"]);
+    ninety = times["90fps"];
+
+    // When power mode is normal, time for configs updates.
+    mRefreshRateStats->setConfigMode(CONFIG_ID_60);
+    std::this_thread::sleep_for(std::chrono::milliseconds(2));
+    times = mRefreshRateStats->getTotalTimes();
+    ASSERT_EQ(screenOff, times["ScreenOff"]);
+    ASSERT_EQ(ninety, times["90fps"]);
+    ASSERT_LT(sixty, times["60fps"]);
+    sixty = times["60fps"];
+
+    mRefreshRateStats->setConfigMode(CONFIG_ID_90);
+    std::this_thread::sleep_for(std::chrono::milliseconds(2));
+    times = mRefreshRateStats->getTotalTimes();
+    ASSERT_EQ(screenOff, times["ScreenOff"]);
+    ASSERT_LT(ninety, times["90fps"]);
+    ASSERT_EQ(sixty, times["60fps"]);
+    ninety = times["90fps"];
+
+    mRefreshRateStats->setConfigMode(CONFIG_ID_60);
+    std::this_thread::sleep_for(std::chrono::milliseconds(2));
+    times = mRefreshRateStats->getTotalTimes();
+    ASSERT_EQ(screenOff, times["ScreenOff"]);
+    ASSERT_EQ(ninety, times["90fps"]);
+    ASSERT_LT(sixty, times["60fps"]);
+    sixty = times["60fps"];
+
+    // Because the power mode is not HWC_POWER_MODE_NORMAL, switching the config
+    // does not update refresh rates that come from the config.
+    mRefreshRateStats->setPowerMode(HWC_POWER_MODE_DOZE);
+    mRefreshRateStats->setConfigMode(CONFIG_ID_90);
+    std::this_thread::sleep_for(std::chrono::milliseconds(2));
+    times = mRefreshRateStats->getTotalTimes();
+    ASSERT_LT(screenOff, times["ScreenOff"]);
+    ASSERT_EQ(ninety, times["90fps"]);
+    ASSERT_EQ(sixty, times["60fps"]);
+    screenOff = times["ScreenOff"];
+
+    mRefreshRateStats->setConfigMode(CONFIG_ID_60);
+    std::this_thread::sleep_for(std::chrono::milliseconds(2));
+    times = mRefreshRateStats->getTotalTimes();
+    ASSERT_LT(screenOff, times["ScreenOff"]);
+    ASSERT_EQ(ninety, times["90fps"]);
+    ASSERT_EQ(sixty, times["60fps"]);
+}
+} // namespace
+} // namespace scheduler
+} // namespace android
diff --git a/services/surfaceflinger/tests/unittests/TestableSurfaceFlinger.h b/services/surfaceflinger/tests/unittests/TestableSurfaceFlinger.h
index 687941a..2a8dda6 100644
--- a/services/surfaceflinger/tests/unittests/TestableSurfaceFlinger.h
+++ b/services/surfaceflinger/tests/unittests/TestableSurfaceFlinger.h
@@ -335,11 +335,11 @@
         void setExpensiveRenderingExpected(hwc2_display_t, bool) override {}
     };
 
-    struct HWC2Display : public HWC2::Display {
+    struct HWC2Display : public HWC2::impl::Display {
         HWC2Display(Hwc2::Composer& composer, Hwc2::PowerAdvisor& advisor,
                     const std::unordered_set<HWC2::Capability>& capabilities, hwc2_display_t id,
                     HWC2::DisplayType type)
-              : HWC2::Display(composer, advisor, capabilities, id, type) {}
+              : HWC2::impl::Display(composer, advisor, capabilities, id, type) {}
         ~HWC2Display() {
             // Prevents a call to disable vsyncs.
             mType = HWC2::DisplayType::Invalid;
diff --git a/services/surfaceflinger/tests/unittests/mock/DisplayHardware/MockDisplay.cpp b/services/surfaceflinger/tests/unittests/mock/DisplayHardware/MockDisplay.cpp
new file mode 100644
index 0000000..2ec37c1
--- /dev/null
+++ b/services/surfaceflinger/tests/unittests/mock/DisplayHardware/MockDisplay.cpp
@@ -0,0 +1,29 @@
+/*
+ * Copyright 2019 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include "mock/DisplayHardware/MockDisplay.h"
+
+namespace android {
+namespace Hwc2 {
+namespace mock {
+
+// Explicit default instantiation is recommended.
+Display::Display() = default;
+Display::~Display() = default;
+
+} // namespace mock
+} // namespace Hwc2
+} // namespace android
\ No newline at end of file
diff --git a/services/surfaceflinger/tests/unittests/mock/DisplayHardware/MockDisplay.h b/services/surfaceflinger/tests/unittests/mock/DisplayHardware/MockDisplay.h
new file mode 100644
index 0000000..d7e20c4
--- /dev/null
+++ b/services/surfaceflinger/tests/unittests/mock/DisplayHardware/MockDisplay.h
@@ -0,0 +1,86 @@
+/*
+ * Copyright 2019 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#pragma once
+
+#include <gmock/gmock.h>
+
+#include "DisplayHardware/HWC2.h"
+
+using HWC2::Error;
+using HWC2::Layer;
+
+namespace android {
+namespace Hwc2 {
+namespace mock {
+
+class Display : public HWC2::Display {
+public:
+    Display();
+    ~Display();
+
+    MOCK_CONST_METHOD0(getId, hwc2_layer_t());
+    MOCK_CONST_METHOD0(isConnected, bool());
+    MOCK_METHOD1(setConnected, void(bool));
+    MOCK_CONST_METHOD0(getCapabilities, const std::unordered_set<HWC2::DisplayCapability>&());
+
+    MOCK_METHOD0(acceptChanges, Error());
+    MOCK_METHOD1(createLayer, Error(Layer**));
+    MOCK_METHOD1(destroyLayer, Error(Layer*));
+    MOCK_CONST_METHOD1(getActiveConfig, Error(std::shared_ptr<const Config>*));
+    MOCK_CONST_METHOD1(getActiveConfigIndex, Error(int* outIndex));
+    MOCK_METHOD1(getChangedCompositionTypes, Error(std::unordered_map<Layer*, HWC2::Composition>*));
+    MOCK_CONST_METHOD1(getColorModes, Error(std::vector<android::ui::ColorMode>*));
+
+    MOCK_CONST_METHOD0(getSupportedPerFrameMetadata, int32_t());
+    MOCK_CONST_METHOD2(getRenderIntents,
+                       Error(android::ui::ColorMode, std::vector<android::ui::RenderIntent>*));
+    MOCK_METHOD2(getDataspaceSaturationMatrix, Error(android::ui::Dataspace, android::mat4*));
+    MOCK_CONST_METHOD0(getConfigs, std::vector<std::shared_ptr<const Config>>());
+
+    MOCK_CONST_METHOD1(getName, Error(std::string*));
+    MOCK_METHOD2(getRequests,
+                 Error(HWC2::DisplayRequest*, std::unordered_map<Layer*, HWC2::LayerRequest>*));
+    MOCK_CONST_METHOD1(getType, Error(HWC2::DisplayType*));
+    MOCK_CONST_METHOD1(supportsDoze, Error(bool*));
+    MOCK_CONST_METHOD1(getHdrCapabilities, Error(android::HdrCapabilities*));
+    MOCK_CONST_METHOD3(getDisplayedContentSamplingAttributes,
+                       Error(android::ui::PixelFormat*, android::ui::Dataspace*, uint8_t*));
+    MOCK_CONST_METHOD3(setDisplayContentSamplingEnabled, Error(bool, uint8_t, uint64_t));
+    MOCK_CONST_METHOD3(getDisplayedContentSample,
+                       Error(uint64_t, uint64_t, android::DisplayedFrameStats*));
+    MOCK_CONST_METHOD1(getReleaseFences,
+                       Error(std::unordered_map<Layer*, android::sp<android::Fence>>* outFences));
+    MOCK_METHOD1(present, Error(android::sp<android::Fence>*));
+    MOCK_METHOD1(setActiveConfig, Error(const std::shared_ptr<const HWC2::Display::Config>&));
+    MOCK_METHOD4(setClientTarget,
+                 Error(uint32_t, const android::sp<android::GraphicBuffer>&,
+                       const android::sp<android::Fence>&, android::ui::Dataspace));
+    MOCK_METHOD2(setColorMode, Error(android::ui::ColorMode, android::ui::RenderIntent));
+    MOCK_METHOD2(setColorTransform, Error(const android::mat4&, android_color_transform_t));
+    MOCK_METHOD2(setOutputBuffer,
+                 Error(const android::sp<android::GraphicBuffer>&,
+                       const android::sp<android::Fence>&));
+    MOCK_METHOD1(setPowerMode, Error(HWC2::PowerMode));
+    MOCK_METHOD1(setVsyncEnabled, Error(HWC2::Vsync));
+    MOCK_METHOD2(validate, Error(uint32_t*, uint32_t*));
+    MOCK_METHOD4(presentOrValidate,
+                 Error(uint32_t*, uint32_t*, android::sp<android::Fence>*, uint32_t*));
+};
+
+} // namespace mock
+} // namespace Hwc2
+} // namespace android
\ No newline at end of file