Update overlay scrollbars

cc/layers/painted_scrollbar_layer_impl.cc

 // 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.
 
 #include "cc/layers/painted_scrollbar_layer_impl.h"
 
 #include <algorithm>
 
 #include "cc/animation/scrollbar_animation_controller.h"
 #include "cc/layers/layer.h"
@@ skipping 151 matching lines @@
   if (track_length_ == track_length)
     return;
   track_length_ = track_length;
   NoteLayerPropertyChanged();
 }
 
 float PaintedScrollbarLayerImpl::TrackLength() const {
   return track_length_ + (orientation() == VERTICAL ? vertical_adjust() : 0);
 }
 
+bool PaintedScrollbarLayerImpl::IsThumbResizable() const {
+  return false;
+}
+
 const char* PaintedScrollbarLayerImpl::LayerTypeAsString() const {
   return "cc::PaintedScrollbarLayerImpl";
 }
 
 }  // namespace cc