Bug 1239945 part 2 - Drop CommonAnimationManager::ContentOrAncestorHasAnimation; r=dholbert

This was added in bug 780692 to work around assertions that arose due to the
inconsistent state introduced by mini-flushes. However, that workaround
no longer seems necessary. In particular, the crashtest for bug 813372 no
longer reports failed assertions when we remove this method and nor do any
other tests.

I'm not sure exactly what changed about how we do mini-flushes but I suspect
it was bug 960465 or one of the related follow-ups.

layout/base/RestyleManager.cpp

@@ -988,11 +988,9 @@ RestyleManager::ProcessRestyledFrames(nsStyleChangeList& aChangeList)
 #ifdef DEBUG
     // reget frame from content since it may have been regenerated...
     if (changeData->mContent) {
-      if (!CommonAnimationManager::ContentOrAncestorHasAnimation(changeData->mContent)) {
-        nsIFrame* frame = changeData->mContent->GetPrimaryFrame();
-        if (frame) {
-          DebugVerifyStyleTree(frame);
-        }
+      nsIFrame* frame = changeData->mContent->GetPrimaryFrame();
+      if (frame) {
+        DebugVerifyStyleTree(frame);
       }
     } else if (!changeData->mFrame ||
                changeData->mFrame->GetType() != nsGkAtoms::viewportFrame) {

layout/style/AnimationCommon.h

@@ -44,19 +44,6 @@ public:
    */
   void Disconnect();
 
-  // Returns true if aContent or any of its ancestors has an animation
-  // or transition.
-  static bool ContentOrAncestorHasAnimation(nsIContent* aContent) {
-    do {
-      if (aContent->GetProperty(nsGkAtoms::animationsProperty) ||
-          aContent->GetProperty(nsGkAtoms::transitionsProperty)) {
-        return true;
-      }
-    } while ((aContent = aContent->GetParent()));
-
-    return false;
-  }
-
   static bool ExtractComputedValueForTransition(
                   nsCSSProperty aProperty,
                   nsStyleContext* aStyleContext,