cc: Make TransformNodeData scroll offset a ScrollOffset

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"
 #include "cc/base/cc_export.h"
 #include "ui/gfx/geometry/rect.h"
+#include "ui/gfx/geometry/scroll_offset.h"
 #include "ui/gfx/transform.h"
 
 namespace cc {
 
 template <typename T>
 struct CC_EXPORT TreeNode {
   TreeNode() : id(-1), parent_id(-1), owner_id(-1), data() {}
   int id;
   int parent_id;
   int owner_id;
@@ skipping 66 matching lines @@
   // This is used as a fallback when we either cannot adjust raster scale or if
   // the raster scale cannot be extracted from the screen space transform.
   float layer_scale_factor;
 
   // TODO(vollick): will be moved when accelerated effects are implemented.
   float post_local_scale_factor;
 
   gfx::Vector2dF sublayer_scale;
 
   // TODO(vollick): will be moved when accelerated effects are implemented.
-  gfx::Vector2dF scroll_offset;
+  gfx::ScrollOffset scroll_offset;
 
   // We scroll snap where possible, but this has an effect on scroll
   // compensation: the snap is yet more scrolling that must be compensated for.
   // This value stores the snapped amount for this purpose.
   gfx::Vector2dF scroll_snap;
 
   // TODO(vollick): will be moved when accelerated effects are implemented.
   gfx::Vector2dF source_offset;
 
   void set_to_parent(const gfx::Transform& transform) {
@@ skipping 133 matching lines @@
 
   TransformTree transform_tree;
   OpacityTree opacity_tree;
   ClipTree clip_tree;
   bool needs_rebuild;
 };
 
 }  // namespace cc
 
 #endif  // CC_TREES_PROPERTY_TREE_H_