cc: Directly use property trees to calculate clip rect

cc/trees/property_tree.cc

Index: cc/trees/property_tree.cc
diff --git a/cc/trees/property_tree.cc b/cc/trees/property_tree.cc
index 34f8c4989fe2c35cb4c14349a1a029702fcd8bf6..764a318ba3d2255558bbe984b569fecbeb2f8bf2 100644
--- a/cc/trees/property_tree.cc
+++ b/cc/trees/property_tree.cc
@@ -441,8 +441,10 @@ EffectNodeData::EffectNodeData()
       has_animated_opacity(false),
       effect_changed(false),
       num_copy_requests_in_subtree(0),
+      has_unclipped_descendants(false),
       transform_id(0),
-      clip_id(0) {}
+      clip_id(0),
+      target_id(0) {}
 
 EffectNodeData::EffectNodeData(const EffectNodeData& other) = default;
 
@@ -596,6 +598,29 @@ bool TransformTree::ComputeTransform(int source_id,
   return CombineInversesBetween(source_id, dest_id, transform);
 }
 
+bool TransformTree::ComputeTransformWithDifferenceInSublayerScale(
+    int source_id,
+    int dest_id,
+    gfx::Transform* transform) const {
+  bool success = ComputeTransform(source_id, dest_id, transform);
+
+  const TransformNode* dest_node = Node(dest_id);
+  if (!dest_node->data.needs_sublayer_scale)
+    return success;
+
+  transform->matrix().postScale(dest_node->data.sublayer_scale.x(),
+                                dest_node->data.sublayer_scale.y(), 1.f);
+
+  const TransformNode* source_node = Node(source_id);
+  if (source_node->data.sublayer_scale.x() > 0 &&
+      source_node->data.sublayer_scale.y() > 0) {
+    transform->Scale(1.f / source_node->data.sublayer_scale.x(),
+                     1.f / source_node->data.sublayer_scale.y());
+  }
+
+  return success;
+}
+
 bool TransformTree::ComputeTransformWithDestinationSublayerScale(
     int source_id,
     int dest_id,