cc: Re-use transforms from transform nodes when computing visible rects

cc/trees/property_tree.h

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef CC_TREES_PROPERTY_TREE_H_
 #define CC_TREES_PROPERTY_TREE_H_
 
 #include <vector>
 
 #include "base/basictypes.h"
@@ skipping 135 matching lines @@
 
 class CC_EXPORT TransformTree final : public PropertyTree<TransformNode> {
  public:
   // Computes the change of basis transform from node |source_id| to |dest_id|.
   // The function returns false iff the inverse of a singular transform was
   // used (and the result should, therefore, not be trusted).
   bool ComputeTransform(int source_id,
                         int dest_id,
                         gfx::Transform* transform) const;
 
+  // Computes the change of basis transform from node |source_id| to |dest_id|,
+  // including any sublayer scale at |dest_id|.  The function returns false iff
+  // the inverse of a singular transform was used (and the result should,
+  // therefore, not be trusted).
+  bool ComputeTransformWithDestinationSublayerScale(
+      int source_id,
+      int dest_id,
+      gfx::Transform* transform) const;
+
+  // Computes the change of basis transform from node |source_id| to |dest_id|,
+  // including any sublayer scale at |source_id|.  The function returns false
+  // iff the inverse of a singular transform was used (and the result should,
+  // therefore, not be trusted).
+  bool ComputeTransformWithSourceSublayerScale(int source_id,
+                                               int dest_id,
+                                               gfx::Transform* transform) const;
+
   // Returns true iff the nodes indexed by |source_id| and |dest_id| are 2D axis
   // aligned with respect to one another.
   bool Are2DAxisAligned(int source_id, int dest_id) const;
 
   // Updates the parent, target, and screen space transforms and snapping.
   void UpdateTransforms(int id);
 
  private:
   // Returns true iff the node at |desc_id| is a descendant of the node at
   // |anc_id|.
@@ skipping 31 matching lines @@
 class CC_EXPORT PropertyTrees final {
  public:
   TransformTree transform_tree;
   OpacityTree opacity_tree;
   ClipTree clip_tree;
 };
 
 }  // namespace cc
 
 #endif  // CC_TREES_PROPERTY_TREE_H_