Adds getSupportedRefreshRates support

Source values for refresh rates from the RefreshRateSelector
through SurfaceComposerClient.

Test: atest android.display.cts.DisplayTest
BUG: 365163968
Flag: com.android.server.display.feature.flags.enable_get_supported_refresh_rates
Change-Id: I149e6e51b3b3718ef53e522f1fca5650dbbd8b7b
diff --git a/services/surfaceflinger/Scheduler/RefreshRateSelector.cpp b/services/surfaceflinger/Scheduler/RefreshRateSelector.cpp
index 84fa139..7f763e5 100644
--- a/services/surfaceflinger/Scheduler/RefreshRateSelector.cpp
+++ b/services/surfaceflinger/Scheduler/RefreshRateSelector.cpp
@@ -1569,6 +1569,19 @@
     return distance1 < distance2 ? *lowerBound : *std::prev(lowerBound);
 }
 
+std::vector<float> RefreshRateSelector::getSupportedFrameRates() const {
+    std::scoped_lock lock(mLock);
+    // TODO(b/356986687) Remove the limit once we have the anchor list implementation.
+    const size_t frameRatesSize = std::min<size_t>(11, mPrimaryFrameRates.size());
+    std::vector<float> supportedFrameRates;
+    supportedFrameRates.reserve(frameRatesSize);
+    std::transform(mPrimaryFrameRates.rbegin(),
+                   mPrimaryFrameRates.rbegin() + static_cast<int>(frameRatesSize),
+                   std::back_inserter(supportedFrameRates),
+                   [](FrameRateMode mode) { return mode.fps.getValue(); });
+    return supportedFrameRates;
+}
+
 auto RefreshRateSelector::getIdleTimerAction() const -> KernelIdleTimerAction {
     std::lock_guard lock(mLock);
 
diff --git a/services/surfaceflinger/Scheduler/RefreshRateSelector.h b/services/surfaceflinger/Scheduler/RefreshRateSelector.h
index ee3a4f7..508f9d7 100644
--- a/services/surfaceflinger/Scheduler/RefreshRateSelector.h
+++ b/services/surfaceflinger/Scheduler/RefreshRateSelector.h
@@ -441,6 +441,8 @@
 
     std::pair<Fps, Fps> getFrameRateCategoryRates() const { return kFrameRateCategoryRates; }
 
+    std::vector<float> getSupportedFrameRates() const EXCLUDES(mLock);
+
 private:
     friend struct TestableRefreshRateSelector;