Bug 1341987 - Part 4: Use nsIFrame's nsPresContext instead of getting from element. r=birtles

MozReview-Commit-ID: 3pWt7d2MKsZ

--HG--
extra : rebase_source : cb34e1aa141d3a6aaa13f3482c8abf1cf83c14f9

dom/animation/KeyframeEffectReadOnly.cpp

@@ -1360,13 +1360,7 @@ KeyframeEffectReadOnly::CanThrottleTransformChanges(nsIFrame& aFrame) const
     return true;
   }
 
-  nsPresContext* presContext = GetPresContext();
-  // CanThrottleTransformChanges is only called as part of a refresh driver tick
-  // in which case we expect to has a pres context.
-  MOZ_ASSERT(presContext);
-
-  TimeStamp now =
-    presContext->RefreshDriver()->MostRecentRefresh();
+  TimeStamp now = aFrame.PresContext()->RefreshDriver()->MostRecentRefresh();
 
   EffectSet* effectSet = EffectSet::GetEffectSet(mTarget->mElement,
                                                  mTarget->mPseudoType);