Bug 1389215 - Don't layerize in response to margin changes. r=mattwoodrow

MozReview-Commit-ID: Ahr3g1NAoQ7

--HG--
extra : rebase_source : a6462769096b8737e58227259ac1f72581c6ed70

layout/painting/ActiveLayerTracker.cpp

@@ -45,10 +45,6 @@ public:
     ACTIVITY_TOP,
     ACTIVITY_RIGHT,
     ACTIVITY_BOTTOM,
-    ACTIVITY_MARGIN_LEFT,
-    ACTIVITY_MARGIN_TOP,
-    ACTIVITY_MARGIN_RIGHT,
-    ACTIVITY_MARGIN_BOTTOM,
     ACTIVITY_BACKGROUND_POSITION,
 
     ACTIVITY_SCALE,
@@ -80,10 +76,6 @@ public:
     case eCSSProperty_top: return ACTIVITY_TOP;
     case eCSSProperty_right: return ACTIVITY_RIGHT;
     case eCSSProperty_bottom: return ACTIVITY_BOTTOM;
-    case eCSSProperty_margin_left: return ACTIVITY_MARGIN_LEFT;
-    case eCSSProperty_margin_top: return ACTIVITY_MARGIN_TOP;
-    case eCSSProperty_margin_right: return ACTIVITY_MARGIN_RIGHT;
-    case eCSSProperty_margin_bottom: return ACTIVITY_MARGIN_BOTTOM;
     case eCSSProperty_background_position: return ACTIVITY_BACKGROUND_POSITION;
     case eCSSProperty_background_position_x: return ACTIVITY_BACKGROUND_POSITION;
     case eCSSProperty_background_position_y: return ACTIVITY_BACKGROUND_POSITION;
@@ -449,18 +441,14 @@ ActiveLayerTracker::IsStyleAnimated(nsDisplayListBuilder* aBuilder,
 }
 
 /* static */ bool
-ActiveLayerTracker::IsOffsetOrMarginStyleAnimated(nsIFrame* aFrame)
+ActiveLayerTracker::IsOffsetStyleAnimated(nsIFrame* aFrame)
 {
   LayerActivity* layerActivity = GetLayerActivity(aFrame);
   if (layerActivity) {
     if (layerActivity->mRestyleCounts[LayerActivity::ACTIVITY_LEFT] >= 2 ||
         layerActivity->mRestyleCounts[LayerActivity::ACTIVITY_TOP] >= 2 ||
         layerActivity->mRestyleCounts[LayerActivity::ACTIVITY_RIGHT] >= 2 ||
-        layerActivity->mRestyleCounts[LayerActivity::ACTIVITY_BOTTOM] >= 2 ||
-        layerActivity->mRestyleCounts[LayerActivity::ACTIVITY_MARGIN_LEFT] >= 2 ||
-        layerActivity->mRestyleCounts[LayerActivity::ACTIVITY_MARGIN_TOP] >= 2 ||
-        layerActivity->mRestyleCounts[LayerActivity::ACTIVITY_MARGIN_RIGHT] >= 2 ||
-        layerActivity->mRestyleCounts[LayerActivity::ACTIVITY_MARGIN_BOTTOM] >= 2) {
+        layerActivity->mRestyleCounts[LayerActivity::ACTIVITY_BOTTOM] >= 2) {
       return true;
     }
   }

layout/painting/ActiveLayerTracker.h

@@ -86,7 +86,7 @@ public:
    * Return true if any of aFrame's offset property styles should be considered
    * as being animated for constructing active layers.
    */
-  static bool IsOffsetOrMarginStyleAnimated(nsIFrame* aFrame);
+  static bool IsOffsetStyleAnimated(nsIFrame* aFrame);
   /**
    * Return true if aFrame's background-position-x or background-position-y
    * property is animated.

layout/painting/nsDisplayList.cpp

@@ -1501,7 +1501,7 @@ nsDisplayListBuilder::IsAnimatedGeometryRoot(nsIFrame* aFrame,
 
   if (nsLayoutUtils::IsPopup(aFrame))
     return AGR_YES;
-  if (ActiveLayerTracker::IsOffsetOrMarginStyleAnimated(aFrame)) {
+  if (ActiveLayerTracker::IsOffsetStyleAnimated(aFrame)) {
     const bool inBudget = AddToAGRBudget(aFrame);
     if (inBudget) {
       return AGR_YES;

layout/style/nsDOMCSSAttrDeclaration.cpp

@@ -211,8 +211,6 @@ nsDOMCSSAttributeDeclaration::SetPropertyValue(const nsCSSPropertyID aPropID,
   if (aPropID == eCSSProperty_opacity || aPropID == eCSSProperty_transform ||
       aPropID == eCSSProperty_left || aPropID == eCSSProperty_top ||
       aPropID == eCSSProperty_right || aPropID == eCSSProperty_bottom ||
-      aPropID == eCSSProperty_margin_left || aPropID == eCSSProperty_margin_top ||
-      aPropID == eCSSProperty_margin_right || aPropID == eCSSProperty_margin_bottom ||
       aPropID == eCSSProperty_background_position_x ||
       aPropID == eCSSProperty_background_position_y ||
       aPropID == eCSSProperty_background_position) {