SF: Avoid registering DisplayDevice with Scheduler

The Scheduler should only care about the RefreshRateSelector part, and
should not needlessly extend the compositionengine::Display's lifetime
until the DisplayDevice is unregistered.

Make Scheduler::registerDisplay infallible, such that SurfaceFlinger::
processDisplayChanged does not need to unregister before registering.

Bug: 241285191
Test: libsurfaceflinger_unittest
Change-Id: I12b3855167e98f48ae368d39264edcb456efb293
diff --git a/services/surfaceflinger/tests/unittests/TestableScheduler.h b/services/surfaceflinger/tests/unittests/TestableScheduler.h
index 2814d38..95c9915 100644
--- a/services/surfaceflinger/tests/unittests/TestableScheduler.h
+++ b/services/surfaceflinger/tests/unittests/TestableScheduler.h
@@ -32,15 +32,13 @@
 
 class TestableScheduler : public Scheduler, private ICompositor {
 public:
-    TestableScheduler(std::shared_ptr<RefreshRateSelector> selectorPtr,
-                      ISchedulerCallback& callback)
+    TestableScheduler(RefreshRateSelectorPtr selectorPtr, ISchedulerCallback& callback)
           : TestableScheduler(std::make_unique<mock::VsyncController>(),
                               std::make_unique<mock::VSyncTracker>(), std::move(selectorPtr),
                               callback) {}
 
     TestableScheduler(std::unique_ptr<VsyncController> controller,
-                      std::unique_ptr<VSyncTracker> tracker,
-                      std::shared_ptr<RefreshRateSelector> selectorPtr,
+                      std::unique_ptr<VSyncTracker> tracker, RefreshRateSelectorPtr selectorPtr,
                       ISchedulerCallback& callback)
           : Scheduler(*this, callback, Feature::kContentDetection) {
         mVsyncSchedule.emplace(VsyncSchedule(std::move(tracker), nullptr, std::move(controller)));
@@ -68,16 +66,15 @@
     auto& mutablePrimaryHWVsyncEnabled() { return mPrimaryHWVsyncEnabled; }
     auto& mutableHWVsyncAvailable() { return mHWVsyncAvailable; }
 
-    auto& mutableLayerHistory() { return mLayerHistory; }
+    auto refreshRateSelector() { return holdRefreshRateSelector(); }
+    bool hasRefreshRateSelectors() const { return !mRefreshRateSelectors.empty(); }
 
-    auto& mutableDisplays() { return mDisplays; }
+    auto& mutableLayerHistory() { return mLayerHistory; }
 
     size_t layerHistorySize() NO_THREAD_SAFETY_ANALYSIS {
         return mLayerHistory.mActiveLayerInfos.size() + mLayerHistory.mInactiveLayerInfos.size();
     }
 
-    auto refreshRateSelector() { return holdRefreshRateSelector(); }
-
     size_t getNumActiveLayers() NO_THREAD_SAFETY_ANALYSIS {
         return mLayerHistory.mActiveLayerInfos.size();
     }