Bug 1271432 - When combining event regions across layers, don't expand the regions that shouldn't be expanded. r=tnikkel

MozReview-Commit-ID: 6GlYiJAm7rO

layout/base/FrameLayerBuilder.cpp

@@ -3282,25 +3282,25 @@ void ContainerState::FinishPaintedLayerData(PaintedLayerData& aData, FindOpaqueB
       containingPaintedLayerData->mMaybeHitRegion.SimplifyOutward(8);
     }
     nsLayoutUtils::TransformToAncestorAndCombineRegions(
-      data->mHitRegion.GetBounds(),
+      data->mHitRegion,
       mContainerReferenceFrame,
       containingPaintedLayerData->mReferenceFrame,
       &containingPaintedLayerData->mHitRegion,
       &containingPaintedLayerData->mMaybeHitRegion);
     nsLayoutUtils::TransformToAncestorAndCombineRegions(
-      data->mNoActionRegion.GetBounds(),
+      data->mNoActionRegion,
       mContainerReferenceFrame,
       containingPaintedLayerData->mReferenceFrame,
       &containingPaintedLayerData->mNoActionRegion,
       &containingPaintedLayerData->mDispatchToContentHitRegion);
     nsLayoutUtils::TransformToAncestorAndCombineRegions(
-      data->mHorizontalPanRegion.GetBounds(),
+      data->mHorizontalPanRegion,
       mContainerReferenceFrame,
       containingPaintedLayerData->mReferenceFrame,
       &containingPaintedLayerData->mHorizontalPanRegion,
       &containingPaintedLayerData->mDispatchToContentHitRegion);
     nsLayoutUtils::TransformToAncestorAndCombineRegions(
-      data->mVerticalPanRegion.GetBounds(),
+      data->mVerticalPanRegion,
       mContainerReferenceFrame,
       containingPaintedLayerData->mReferenceFrame,
       &containingPaintedLayerData->mVerticalPanRegion,

layout/base/nsLayoutUtils.cpp

@@ -9015,23 +9015,24 @@ nsLayoutUtils::GetTouchActionFromFrame(nsIFrame* aFrame)
 
 /* static */  void
 nsLayoutUtils::TransformToAncestorAndCombineRegions(
-  const nsRect& aBounds,
+  const nsRegion& aRegion,
   nsIFrame* aFrame,
   const nsIFrame* aAncestorFrame,
   nsRegion* aPreciseTargetDest,
   nsRegion* aImpreciseTargetDest)
 {
-  if (aBounds.IsEmpty()) {
+  if (aRegion.IsEmpty()) {
     return;
   }
-  Matrix4x4 matrix = GetTransformToAncestor(aFrame, aAncestorFrame);
-  Matrix matrix2D;
-  bool isPrecise = (matrix.Is2D(&matrix2D)
-    && !matrix2D.HasNonAxisAlignedTransform());
+  bool isPrecise;
+  nsRegion transformedRegion;
+  for (nsRegion::RectIterator it = aRegion.RectIter(); !it.Done(); it.Next()) {
     nsRect transformed = TransformFrameRectToAncestor(
-    aFrame, aBounds, aAncestorFrame);
+      aFrame, it.Get(), aAncestorFrame, &isPrecise);
+    transformedRegion.OrWith(transformed);
+  }
   nsRegion* dest = isPrecise ? aPreciseTargetDest : aImpreciseTargetDest;
-  dest->OrWith(transformed);
+  dest->OrWith(transformedRegion);
 }
 
 /* static */ bool

layout/base/nsLayoutUtils.h

@@ -2558,7 +2558,7 @@ public:
    */
   static void
   TransformToAncestorAndCombineRegions(
-    const nsRect& aBounds,
+    const nsRegion& aRegion,
     nsIFrame* aFrame,
     const nsIFrame* aAncestorFrame,
     nsRegion* aPreciseTargetDest,