Make scroll offset type of float in cc

cc/input/layer_scroll_offset_delegate.h

 // Copyright 2013 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_INPUT_LAYER_SCROLL_OFFSET_DELEGATE_H_
 #define CC_INPUT_LAYER_SCROLL_OFFSET_DELEGATE_H_
 
 #include "base/basictypes.h"
+#include "ui/gfx/geometry/scroll_offset.h"
 #include "ui/gfx/size_f.h"
-#include "ui/gfx/vector2d_f.h"
 
 namespace cc {
 
 // The LayerScrollOffsetDelegate allows for the embedder to take ownership of
 // the scroll offset of the root layer.
 //
 // The LayerScrollOffsetDelegate is only used on the impl thread.
 class LayerScrollOffsetDelegate {
  public:
   // This is called by the compositor to query the current scroll offset of the
   // layer.
   // There is no requirement that the return values of this method are
   // stable in time (two subsequent calls may yield different results).
   // The return value is not required to be related to the values passed in to
   // the SetTotalScrollOffset method in any way however it is required to be no
   // more than the value passed to the most recent SetMaxScrollOffset call.
-  virtual gfx::Vector2dF GetTotalScrollOffset() = 0;
+  virtual gfx::ScrollOffset GetTotalScrollOffset() = 0;
 
   // This is called by the compositor to notify the delegate of any change to
   // the following parameters:
   // |total_scroll_offset| current scroll offset of the root layer,
   // |max_scroll_offset| total scroll offset upper bound for the root layer,
   // |scrollable_size| root layer scrollable size,
   // |page_scale_factor| current page scale,
   // |min_page_scale_factor| page scale lower limit,
   // |max_page_scale_factor| page scale upper limit.
-  virtual void UpdateRootLayerState(const gfx::Vector2dF& total_scroll_offset,
-                                    const gfx::Vector2dF& max_scroll_offset,
-                                    const gfx::SizeF& scrollable_size,
-                                    float page_scale_factor,
-                                    float min_page_scale_factor,
-                                    float max_page_scale_factor) = 0;
+  virtual void UpdateRootLayerState(
+      const gfx::ScrollOffset& total_scroll_offset,
+      const gfx::ScrollOffset& max_scroll_offset,
+      const gfx::SizeF& scrollable_size,
+      float page_scale_factor,
+      float min_page_scale_factor,
+      float max_page_scale_factor) = 0;
 
   // This is called by the compositor to check whether a delegate-managed fling
   // is active or not.
   virtual bool IsExternalFlingActive() const = 0;
 
  protected:
   LayerScrollOffsetDelegate() {}
   virtual ~LayerScrollOffsetDelegate() {}
 
  private:
   DISALLOW_COPY_AND_ASSIGN(LayerScrollOffsetDelegate);
 };
 
 }  // namespace cc
 
 #endif  // CC_INPUT_LAYER_SCROLL_OFFSET_DELEGATE_H_