Bug 1435022 - Remove the ResumeComposition function from the vsync scheduler. r=sotaro

Having a resume function without a corresponding pause function seems
silly. And the implementation of the function is the same as doing a
force-compose, which is what the call site is intending to do. So we can
just remove this function and do a force-compose instead.

MozReview-Commit-ID: LimMYQhAuEk

--HG--
extra : rebase_source : f10e43c4c4a6f67162b1b473de6c23d8dbdc7a8f

gfx/layers/ipc/CompositorBridgeParent.cpp

@@ -745,7 +745,7 @@ CompositorBridgeParent::ResumeComposition()
   mPaused = false;
 
   Invalidate();
-  mCompositorScheduler->ResumeComposition();
+  mCompositorScheduler->ForceComposeToTarget(nullptr, nullptr);
 
   // if anyone's waiting to make sure that composition really got resumed, tell them
   lock.NotifyAll();

gfx/layers/ipc/CompositorVsyncScheduler.cpp

@@ -367,14 +367,6 @@ CompositorVsyncScheduler::ScheduleTask(already_AddRefed<CancelableRunnable> aTas
   CompositorThreadHolder::Loop()->PostDelayedTask(Move(aTask), 0);
 }
 
-void
-CompositorVsyncScheduler::ResumeComposition()
-{
-  MOZ_ASSERT(CompositorThreadHolder::IsInCompositorThread());
-  mLastCompose = TimeStamp::Now();
-  ComposeToTarget(nullptr);
-}
-
 void
 CompositorVsyncScheduler::ComposeToTarget(gfx::DrawTarget* aTarget, const IntRect* aRect)
 {

gfx/layers/ipc/CompositorVsyncScheduler.h

@@ -51,7 +51,6 @@ public:
   bool NotifyVsync(TimeStamp aVsyncTimestamp);
   void SetNeedsComposite();
 
-  void ResumeComposition();
   void ComposeToTarget(gfx::DrawTarget* aTarget, const gfx::IntRect* aRect = nullptr);
   void PostCompositeTask(TimeStamp aCompositeTimestamp);
   void PostVRTask(TimeStamp aTimestamp);