SF: Fix pacesetter promotion for folded mirroring

The pacesetter display is demoted/promoted in response to a hotplug. On
foldables, the promoted display was hard-coded to the inner display, so
a hotplug while folded would incorrectly use that powered-off display as
the pacesetter, causing system-wide jank until the next fold/unfold.

Fixes: 347248313
Flag: EXEMPT bugfix
Test: Connect and disconnect external display while folded.
Test: Fold and unfold while external display is connected.
Test: Pacesetter is still correct on folded/unfolded boot.
Change-Id: Id5cb29c3cbaa8ed455a15d8be3a32e79a470cce5
diff --git a/services/surfaceflinger/tests/unittests/SchedulerTest.cpp b/services/surfaceflinger/tests/unittests/SchedulerTest.cpp
index 4fb0690..fc54a8b 100644
--- a/services/surfaceflinger/tests/unittests/SchedulerTest.cpp
+++ b/services/surfaceflinger/tests/unittests/SchedulerTest.cpp
@@ -343,12 +343,15 @@
 }
 
 TEST_F(SchedulerTest, chooseDisplayModesMultipleDisplays) {
+    constexpr PhysicalDisplayId kActiveDisplayId = kDisplayId1;
     mScheduler->registerDisplay(kDisplayId1,
                                 std::make_shared<RefreshRateSelector>(kDisplay1Modes,
-                                                                      kDisplay1Mode60->getId()));
+                                                                      kDisplay1Mode60->getId()),
+                                kActiveDisplayId);
     mScheduler->registerDisplay(kDisplayId2,
                                 std::make_shared<RefreshRateSelector>(kDisplay2Modes,
-                                                                      kDisplay2Mode60->getId()));
+                                                                      kDisplay2Mode60->getId()),
+                                kActiveDisplayId);
 
     mScheduler->setDisplayPowerMode(kDisplayId1, hal::PowerMode::ON);
     mScheduler->setDisplayPowerMode(kDisplayId2, hal::PowerMode::ON);
@@ -411,10 +414,10 @@
     {
         // The kDisplayId3 does not support 120Hz, The pacesetter display rate is chosen to be 120
         // Hz. In this case only the display kDisplayId3 choose 60Hz as it does not support 120Hz.
-        mScheduler
-                ->registerDisplay(kDisplayId3,
-                                  std::make_shared<RefreshRateSelector>(kDisplay3Modes,
-                                                                        kDisplay3Mode60->getId()));
+        mScheduler->registerDisplay(kDisplayId3,
+                                    std::make_shared<RefreshRateSelector>(kDisplay3Modes,
+                                                                          kDisplay3Mode60->getId()),
+                                    kActiveDisplayId);
         mScheduler->setDisplayPowerMode(kDisplayId3, hal::PowerMode::ON);
 
         const GlobalSignals globalSignals = {.touch = true};
@@ -457,12 +460,15 @@
 }
 
 TEST_F(SchedulerTest, onFrameSignalMultipleDisplays) {
+    constexpr PhysicalDisplayId kActiveDisplayId = kDisplayId1;
     mScheduler->registerDisplay(kDisplayId1,
                                 std::make_shared<RefreshRateSelector>(kDisplay1Modes,
-                                                                      kDisplay1Mode60->getId()));
+                                                                      kDisplay1Mode60->getId()),
+                                kActiveDisplayId);
     mScheduler->registerDisplay(kDisplayId2,
                                 std::make_shared<RefreshRateSelector>(kDisplay2Modes,
-                                                                      kDisplay2Mode60->getId()));
+                                                                      kDisplay2Mode60->getId()),
+                                kActiveDisplayId);
 
     using VsyncIds = std::vector<std::pair<PhysicalDisplayId, VsyncId>>;
 
@@ -585,7 +591,8 @@
                                 mFlinger.getTimeStats(),
                                 mSchedulerCallback};
 
-    scheduler.registerDisplay(kMode->getPhysicalDisplayId(), vrrSelectorPtr, vrrTracker);
+    scheduler.registerDisplay(kMode->getPhysicalDisplayId(), vrrSelectorPtr, std::nullopt,
+                              vrrTracker);
     vrrSelectorPtr->setActiveMode(kMode->getId(), frameRate);
     scheduler.setRenderRate(kMode->getPhysicalDisplayId(), frameRate, /*applyImmediately*/ false);
     vrrTracker->addVsyncTimestamp(0);
diff --git a/services/surfaceflinger/tests/unittests/TestableScheduler.h b/services/surfaceflinger/tests/unittests/TestableScheduler.h
index 198a5de..f063809 100644
--- a/services/surfaceflinger/tests/unittests/TestableScheduler.h
+++ b/services/surfaceflinger/tests/unittests/TestableScheduler.h
@@ -53,7 +53,7 @@
                       factory, selectorPtr->getActiveMode().fps, timeStats) {
         const auto displayId = selectorPtr->getActiveMode().modePtr->getPhysicalDisplayId();
         registerDisplay(displayId, std::move(selectorPtr), std::move(controller),
-                        std::move(tracker));
+                        std::move(tracker), displayId);
 
         ON_CALL(*this, postMessage).WillByDefault([](sp<MessageHandler>&& handler) {
             // Execute task to prevent broken promise exception on destruction.
@@ -85,14 +85,16 @@
 
     void registerDisplay(
             PhysicalDisplayId displayId, RefreshRateSelectorPtr selectorPtr,
+            std::optional<PhysicalDisplayId> activeDisplayIdOpt = {},
             std::shared_ptr<VSyncTracker> vsyncTracker = std::make_shared<mock::VSyncTracker>()) {
         registerDisplay(displayId, std::move(selectorPtr),
-                        std::make_unique<mock::VsyncController>(), vsyncTracker);
+                        std::make_unique<mock::VsyncController>(), vsyncTracker,
+                        activeDisplayIdOpt.value_or(displayId));
     }
 
     void registerDisplay(PhysicalDisplayId displayId, RefreshRateSelectorPtr selectorPtr,
                          std::unique_ptr<VsyncController> controller,
-                         std::shared_ptr<VSyncTracker> tracker) {
+                         std::shared_ptr<VSyncTracker> tracker, PhysicalDisplayId activeDisplayId) {
         ftl::FakeGuard guard(kMainThreadContext);
         Scheduler::registerDisplayInternal(displayId, std::move(selectorPtr),
                                            std::shared_ptr<VsyncSchedule>(
@@ -101,16 +103,12 @@
                                                                              mock::VSyncDispatch>(),
                                                                      std::move(controller),
                                                                      mockRequestHardwareVsync
-                                                                             .AsStdFunction())));
+                                                                             .AsStdFunction())),
+                                           activeDisplayId);
     }
 
     testing::MockFunction<void(PhysicalDisplayId, bool)> mockRequestHardwareVsync;
 
-    void unregisterDisplay(PhysicalDisplayId displayId) {
-        ftl::FakeGuard guard(kMainThreadContext);
-        Scheduler::unregisterDisplay(displayId);
-    }
-
     void setDisplayPowerMode(PhysicalDisplayId displayId, hal::PowerMode powerMode) {
         ftl::FakeGuard guard(kMainThreadContext);
         Scheduler::setDisplayPowerMode(displayId, powerMode);
diff --git a/services/surfaceflinger/tests/unittests/TestableSurfaceFlinger.h b/services/surfaceflinger/tests/unittests/TestableSurfaceFlinger.h
index 007383b..4197cbd 100644
--- a/services/surfaceflinger/tests/unittests/TestableSurfaceFlinger.h
+++ b/services/surfaceflinger/tests/unittests/TestableSurfaceFlinger.h
@@ -1118,8 +1118,8 @@
                 if (mFlinger.scheduler() && mSchedulerRegistration) {
                     mFlinger.scheduler()->registerDisplay(*physicalId,
                                                           mCreationArgs.refreshRateSelector,
-                                                          std::move(controller),
-                                                          std::move(tracker));
+                                                          std::move(controller), std::move(tracker),
+                                                          mFlinger.mutableActiveDisplayId());
                 }
             }