diff --git a/layout/base/RestyleManager.cpp b/layout/base/RestyleManager.cpp
index aaae80124d3..a736aacccfb 100644
--- a/layout/base/RestyleManager.cpp
+++ b/layout/base/RestyleManager.cpp
@@ -64,6 +64,8 @@ RestyleManager::RestyleManager(nsPresContext* aPresContext)
   , mRebuildAllStyleData(false)
   , mObservingRefreshDriver(false)
   , mInStyleRefresh(false)
+  , mSkipAnimationRules(false)
+  , mPostAnimationRestyles(false)
   , mHoverGeneration(0)
   , mRebuildAllExtraHint(nsChangeHint(0))
   , mLastUpdateForThrottledAnimations(aPresContext->RefreshDriver()->
@@ -1439,6 +1441,13 @@ RestyleManager::RebuildAllStyleData(nsChangeHint aExtraHint)
 #endif
   mPresContext->SetProcessingRestyles(true);
 
+  // Until we get rid of these phases in bug 960465, we need to skip
+  // animation restyles during the non-animation phase, and post
+  // animation restyles so that we restyle those elements again in the
+  // animation phase.
+  mSkipAnimationRules = true;
+  mPostAnimationRestyles = true;
+
   // FIXME (bug 1047928): Many of the callers probably don't need
   // eRestyle_Subtree because they're changing things that affect data
   // computation rather than selector matching; we could have a restyle
@@ -1449,6 +1458,8 @@ RestyleManager::RebuildAllStyleData(nsChangeHint aExtraHint)
                         nsRestyleHint(eRestyle_Subtree |
                                       eRestyle_ForceDescendants));
 
+  mPostAnimationRestyles = false;
+  mSkipAnimationRules = false;
 #ifdef DEBUG
   mIsProcessingRestyles = false;
 #endif
@@ -1539,8 +1550,18 @@ RestyleManager::ProcessPendingRestyles()
     UpdateOnlyAnimationStyles();
   }
 
+  // Until we get rid of these phases in bug 960465, we need to skip
+  // animation restyles during the non-animation phase, and post
+  // animation restyles so that we restyle those elements again in the
+  // animation phase.
+  mSkipAnimationRules = true;
+  mPostAnimationRestyles = true;
+
   mPendingRestyles.ProcessRestyles();
 
+  mPostAnimationRestyles = false;
+  mSkipAnimationRules = false;
+
 #ifdef DEBUG
   uint32_t oldPendingRestyleCount = mPendingRestyles.Count();
 #endif
diff --git a/layout/base/RestyleManager.h b/layout/base/RestyleManager.h
index a5610023880..6acc770aa2a 100644
--- a/layout/base/RestyleManager.h
+++ b/layout/base/RestyleManager.h
@@ -92,6 +92,22 @@ public:
   // track whether off-main-thread animations are up-to-date.
   uint64_t GetAnimationGeneration() const { return mAnimationGeneration; }
 
+  // Whether rule matching should skip styles associated with animation
+  bool SkipAnimationRules() const {
+    MOZ_ASSERT(mSkipAnimationRules || !mPostAnimationRestyles,
+               "inconsistent state");
+    return mSkipAnimationRules;
+  }
+
+  // Whether rule matching should post animation restyles when it skips
+  // styles associated with animation.  Only true when
+  // SkipAnimationRules() is also true.
+  bool PostAnimationRestyles() const {
+    MOZ_ASSERT(mSkipAnimationRules || !mPostAnimationRestyles,
+               "inconsistent state");
+    return mPostAnimationRestyles;
+  }
+
   /**
    * Reparent the style contexts of this frame subtree.  The parent frame of
    * aFrame must be changed to the new parent before this function is called;
@@ -427,6 +443,13 @@ private:
   bool mObservingRefreshDriver : 1;
   // True if we're in the middle of a nsRefreshDriver refresh
   bool mInStyleRefresh : 1;
+  // Whether rule matching should skip styles associated with animation
+  bool mSkipAnimationRules : 1;
+  // Whether rule matching should post animation restyles when it skips
+  // styles associated with animation.  Only true when
+  // mSkipAnimationRules is also true.
+  bool mPostAnimationRestyles : 1;
+
   uint32_t mHoverGeneration;
   nsChangeHint mRebuildAllExtraHint;