Bug 1232577 part 15 - Drop LastStyleUpdateForAllAnimations flag from pres context; r=heycam

nsPresContext contains a mLastStyleUpdateForAllAnimations flag which is simply
used to prevent unnecessarily posting restyles when throttled animations are
already up to date. Since part 13 we now accurately record whether we have
posted a restyle for each throttled animation and only post a restyle if we
have not done so already. As a result, this flag is no longer needed since
calling PostRestyleForThrottledAnimations is effectively a noop when throttled
animations are up-to-date.

dom/animation/EffectCompositor.cpp

@@ -158,7 +158,6 @@ EffectCompositor::RequestRestyle(dom::Element* aElement,
 
   if (aRestyleType == RestyleType::Layer) {
     // Prompt layers to re-sync their animations.
-    mPresContext->ClearLastStyleUpdateForAllAnimations();
     mPresContext->RestyleManager()->IncrementAnimationGeneration();
     EffectSet* effectSet =
       EffectSet::GetEffectSet(aElement, aPseudoType);

layout/base/nsPresContext.cpp

@@ -1050,9 +1050,6 @@ nsPresContext::Init(nsDeviceContext* aDeviceContext)
     }
   }
 
-  // Initialise refresh tick counters for OMTA
-  mLastStyleUpdateForAllAnimations = mRefreshDriver->MostRecentRefresh();
-
   // Initialize restyle manager after initializing the refresh driver.
   // Since RestyleManager is also the name of a method of nsPresContext,
   // it is necessary to prefix the class with the mozilla namespace
@@ -1762,24 +1759,6 @@ nsPresContext::Detach()
   }
 }
 
-bool
-nsPresContext::StyleUpdateForAllAnimationsIsUpToDate() const
-{
-  return mLastStyleUpdateForAllAnimations == mRefreshDriver->MostRecentRefresh();
-}
-
-void
-nsPresContext::TickLastStyleUpdateForAllAnimations()
-{
-  mLastStyleUpdateForAllAnimations = mRefreshDriver->MostRecentRefresh();
-}
-
-void
-nsPresContext::ClearLastStyleUpdateForAllAnimations()
-{
-  mLastStyleUpdateForAllAnimations = TimeStamp();
-}
-
 bool
 nsPresContext::BidiEnabledExternal() const
 {

layout/base/nsPresContext.h

@@ -707,13 +707,6 @@ public:
     mDrawColorBackground = aCanDraw;
   }
 
-  /**
-   * Getter and setters for OMTA time counters
-   */
-  bool StyleUpdateForAllAnimationsIsUpToDate() const;
-  void TickLastStyleUpdateForAllAnimations();
-  void ClearLastStyleUpdateForAllAnimations();
-
   /**
    *  Check if bidi enabled (set depending on the presence of RTL
    *  characters or when default directionality is RTL).

layout/base/nsPresShell.cpp

@@ -3966,12 +3966,8 @@ PresShell::FlushPendingNotifications(mozilla::ChangesToFlush aFlush)
         mDocument->GetAnimationController()->FlushResampleRequests();
       }
 
-      if (aFlush.mFlushAnimations &&
-          !mPresContext->StyleUpdateForAllAnimationsIsUpToDate()) {
-        if (mPresContext->EffectCompositor()) {
-          mPresContext->EffectCompositor()->PostRestyleForThrottledAnimations();
-        }
-        mPresContext->TickLastStyleUpdateForAllAnimations();
+      if (aFlush.mFlushAnimations && mPresContext->EffectCompositor()) {
+        mPresContext->EffectCompositor()->PostRestyleForThrottledAnimations();
       }
 
       // The FlushResampleRequests() above flushed style changes.

layout/base/nsRefreshDriver.cpp

@@ -1709,10 +1709,6 @@ nsRefreshDriver::Tick(int64_t aNowEpoch, TimeStamp aNowTime)
         if (tracingStyleFlush) {
           profiler_tracing("Paint", "Styles", TRACING_INTERVAL_END);
         }
-
-        if (!nsLayoutUtils::AreAsyncAnimationsEnabled()) {
-          mPresContext->TickLastStyleUpdateForAllAnimations();
-        }
       }
     } else if  (i == 1) {
       // This is the Flush_Layout case.