cc : Move screen space scale factor to root transform node

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 <stddef.h>
 
 #include <memory>
@@ skipping 209 matching lines @@
   float page_scale_factor() const { return page_scale_factor_; }
 
   void set_device_scale_factor(float device_scale_factor) {
     device_scale_factor_ = device_scale_factor;
   }
   float device_scale_factor() const { return device_scale_factor_; }
 
   void SetDeviceTransform(const gfx::Transform& transform,
                           gfx::PointF root_position);
   void SetDeviceTransformScaleFactor(const gfx::Transform& transform);
+  void SetScreenSpaceScale(float device_scale_factor,
+                           float page_scale_factor_for_root,
+                           gfx::Transform device_transform);
+
   float device_transform_scale_factor() const {
     return device_transform_scale_factor_;
   }
 
   void UpdateInnerViewportContainerBoundsDelta();
 
   void UpdateOuterViewportContainerBoundsDelta();
 
   void AddNodeAffectedByInnerViewportBoundsDelta(int node_id);
   void AddNodeAffectedByOuterViewportBoundsDelta(int node_id);
@@ skipping 428 matching lines @@
   DrawTransforms& GetDrawTransforms(int transform_id, int effect_id) const;
   DrawTransformData& FetchDrawTransformsDataFromCache(int transform_id,
                                                       int effect_id) const;
 
   PropertyTreesCachedData cached_data_;
 };
 
 }  // namespace cc
 
 #endif  // CC_TREES_PROPERTY_TREE_H_