Revert of Cleanup viewport scrolling for future scroll customization work.

cc/trees/layer_tree_host_impl.h

 // Copyright 2011 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_LAYER_TREE_HOST_IMPL_H_
 #define CC_TREES_LAYER_TREE_HOST_IMPL_H_
 
 #include <set>
 #include <string>
 #include <vector>
@@ skipping 509 matching lines @@
 
   bool prepare_tiles_needed() const { return tile_priorities_dirty_; }
 
   FrameTimingTracker* frame_timing_tracker() {
     return frame_timing_tracker_.get();
   }
 
   gfx::Vector2dF ScrollLayer(LayerImpl* layer_impl,
                              const gfx::Vector2dF& delta,
                              const gfx::Point& viewport_point,
-                             bool is_direct_manipulation);
+                             bool is_wheel_scroll);
 
   // Record main frame timing information.
   // |start_of_main_frame_args| is the BeginFrameArgs of the beginning of the
   // main frame (ie the frame that kicked off the main frame).
   // |expected_next_main_frame_args| is the BeginFrameArgs of the frame that
   // follows the completion of the main frame (whether it is activation or some
   // other completion, such as early out). Note that if there is a main frame
   // scheduled in that frame, then this BeginFrameArgs will become the main
   // frame args. However, if no such frame is scheduled, then this _would_ be
   // the main frame args if it was scheduled.
@@ skipping 239 matching lines @@
   scoped_ptr<FrameTimingTracker> frame_timing_tracker_;
 
   scoped_ptr<Viewport> viewport_;
 
   DISALLOW_COPY_AND_ASSIGN(LayerTreeHostImpl);
 };
 
 }  // namespace cc
 
 #endif  // CC_TREES_LAYER_TREE_HOST_IMPL_H_