Don't allow merging within an animated layer

Also isolates layer translation fudging so as to not affect child transforms.

bug:6585341
Change-Id: If416c6fad90ee37fbe3438e01706b34e683165b7

2 files changed, 12 insertions, 7 deletions

diff --git a/Source/WebCore/platform/graphics/android/layers/LayerAndroid.cpp b/Source/WebCore/platform/graphics/android/layers/LayerAndroid.cpp
index 293bbbc1f..0f01fe2b9 100644
--- a/Source/WebCore/platform/graphics/android/layers/LayerAndroid.cpp
+++ b/Source/WebCore/platform/graphics/android/layers/LayerAndroid.cpp
@@ -122,6 +122,7 @@ LayerAndroid::LayerAndroid(const LayerAndroid& layer) : Layer(layer),
 
     m_transform = layer.m_transform;
     m_drawTransform = layer.m_drawTransform;
+    m_drawTransformUnfudged = layer.m_drawTransformUnfudged;
     m_childrenTransform = layer.m_childrenTransform;
     m_dirtyRegion = layer.m_dirtyRegion;
 
@@ -407,6 +408,7 @@ void LayerAndroid::updateLocalTransformAndClip(const TransformationMatrix& paren
                                 -originY,
                                 -anchorPointZ());
 
+    m_drawTransformUnfudged = m_drawTransform;
     if (m_drawTransform.isIdentityOrTranslation()
         && surface() && surface()->allowTransformFudging()) {
         // adjust the translation coordinates of the draw transform matrix so
@@ -455,9 +457,8 @@ void LayerAndroid::updateGLPositionsAndScale(const TransformationMatrix& parentM
     setDrawOpacity(opacity);
 
     // constantly recalculate the draw transform of layers that may require it (and their children)
-    forceCalculation |= isPositionFixed()
-        || contentIsScrollable()
-        || (m_animations.size() != 0);
+    forceCalculation |= hasDynamicTransform();
+
     forceCalculation &= !(disableFixedElemUpdate && isPositionFixed());
     if (forceCalculation)
         updateLocalTransformAndClip(parentMatrix, clipping);
@@ -465,7 +466,7 @@ void LayerAndroid::updateGLPositionsAndScale(const TransformationMatrix& parentM
     if (!countChildren() || !m_visible)
         return;
 
-    TransformationMatrix localMatrix = m_drawTransform;
+    TransformationMatrix localMatrix = m_drawTransformUnfudged;
 
     // Flatten to 2D if the layer doesn't preserve 3D.
     if (!preserves3D()) {
@@ -682,7 +683,7 @@ void LayerAndroid::assignSurfaces(LayerMergeState* mergeState)
     mergeState->currentSurface->addLayer(this, m_drawTransform);
     m_surface = mergeState->currentSurface;
 
-    if (contentIsScrollable() || isPositionFixed()) {
+    if (hasDynamicTransform()) {
         // disable layer merging within the children of these layer types
         mergeState->nonMergeNestedLevel++;
     }
@@ -704,7 +705,7 @@ void LayerAndroid::assignSurfaces(LayerMergeState* mergeState)
         mergeState->depth--;
     }
 
-    if (contentIsScrollable() || isPositionFixed()) {
+    if (hasDynamicTransform()) {
         // re-enable joining
         mergeState->nonMergeNestedLevel--;
 
diff --git a/Source/WebCore/platform/graphics/android/layers/LayerAndroid.h b/Source/WebCore/platform/graphics/android/layers/LayerAndroid.h
index c56d50a4d..f821d894b 100644
--- a/Source/WebCore/platform/graphics/android/layers/LayerAndroid.h
+++ b/Source/WebCore/platform/graphics/android/layers/LayerAndroid.h
@@ -166,7 +166,7 @@ public:
     void setPreserves3D(bool value) { m_preserves3D = value; }
     void setAnchorPointZ(float z) { m_anchorPointZ = z; }
     float anchorPointZ() { return m_anchorPointZ; }
-    void setDrawTransform(const TransformationMatrix& transform) { m_drawTransform = transform; }
+    void setDrawTransform(const TransformationMatrix& transform) { m_drawTransform = m_drawTransformUnfudged = transform; }
     virtual const TransformationMatrix* drawTransform() const { return &m_drawTransform; }
     void setChildrenTransform(const TransformationMatrix& t) { m_childrenTransform = t; }
     void setDrawClip(const FloatRect& rect) { m_clippingRect = rect; }
@@ -300,11 +300,15 @@ protected:
     virtual void onDraw(SkCanvas*, SkScalar opacity, android::DrawExtra* extra, PaintStyle style);
     virtual InvalidateFlags onSetHwAccelerated(bool hwAccelerated) { return InvalidateNone; }
     TransformationMatrix m_drawTransform;
+    TransformationMatrix m_drawTransformUnfudged;
     int m_uniqueId;
 
 private:
     void updateLocalTransformAndClip(const TransformationMatrix& parentMatrix,
                                      const FloatRect& clip);
+    bool hasDynamicTransform() {
+        return contentIsScrollable() || isPositionFixed() || (m_animations.size() != 0);
+    }
 
 #if DUMP_NAV_CACHE
     friend class CachedLayer::Debug; // debugging access only