Revert of "Converted LayerImpl::bounds() to return SizeF."

cc/trees/layer_tree_host_impl.cc

 // 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.
 
 #include "cc/trees/layer_tree_host_impl.h"
 
 #include <algorithm>
 #include <limits>
 
 #include "base/basictypes.h"
@@ skipping 2642 matching lines @@
 
   for (LayerImpl* layer_impl = CurrentlyScrollingLayer();
        layer_impl;
        layer_impl = layer_impl->parent()) {
     if (!layer_impl->scrollable())
       continue;
 
     if (!layer_impl->HasScrollbar(VERTICAL))
       continue;
 
-    float height = layer_impl->scroll_clip_layer()
-        ? layer_impl->scroll_clip_layer()->bounds().height()
-        : 0;
+    float height = layer_impl->clip_height();
 
     // These magical values match WebKit and are designed to scroll nearly the
     // entire visible content height but leave a bit of overlap.
     float page = std::max(height * 0.875f, 1.f);
     if (direction == SCROLL_BACKWARD)
       page = -page;
 
     gfx::Vector2dF delta = gfx::Vector2dF(0.f, page);
 
     gfx::Vector2dF applied_delta = ScrollLayerWithLocalDelta(layer_impl, delta);
@@ skipping 704 matching lines @@
 }
 
 void LayerTreeHostImpl::UnregisterPictureLayerImpl(PictureLayerImpl* layer) {
   std::vector<PictureLayerImpl*>::iterator it =
       std::find(picture_layers_.begin(), picture_layers_.end(), layer);
   DCHECK(it != picture_layers_.end());
   picture_layers_.erase(it);
 }
 
 }  // namespace cc