Remove scroll distribution code from Layer/LayerTreeHost.

cc/layers/layer.cc

 // Copyright 2010 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/layer.h"
 
 #include <algorithm>
 
 #include "base/debug/trace_event.h"
 #include "base/location.h"
@@ skipping 656 matching lines @@
 void Layer::RemoveClipChild(Layer* child) {
   clip_children_->erase(child);
   if (clip_children_->empty())
     clip_children_.reset();
   SetNeedsCommit();
 }
 
 void Layer::SetScrollOffset(gfx::Vector2d scroll_offset) {
   DCHECK(IsPropertyChangeAllowed());
 
-  if (layer_tree_host()) {
-    scroll_offset = layer_tree_host()->DistributeScrollOffsetToViewports(
-        scroll_offset, this);
-  }
-
   if (scroll_offset_ == scroll_offset)
     return;
   scroll_offset_ = scroll_offset;
   SetNeedsCommit();
 }
 
 void Layer::SetScrollOffsetFromImplSide(const gfx::Vector2d& scroll_offset) {
   DCHECK(IsPropertyChangeAllowed());
   // This function only gets called during a BeginMainFrame, so there
   // is no need to call SetNeedsUpdate here.
   DCHECK(layer_tree_host_ && layer_tree_host_->CommitRequested());
   if (scroll_offset_ == scroll_offset)
     return;
   scroll_offset_ = scroll_offset;
   SetNeedsPushProperties();
   if (!did_scroll_callback_.is_null())
     did_scroll_callback_.Run();
   // The callback could potentially change the layer structure:
   // "this" may have been destroyed during the process.
 }
 
-// TODO(wjmaclean) We should template this and put it into LayerTreeHostCommon
-// so that both Layer and LayerImpl are using the same code. In order
-// to template it we should avoid calling layer_tree_host() by giving
-// Layer/LayerImpl local accessors for page_scale_layer() and
-// page_scale_factor().
-gfx::Vector2d Layer::MaxScrollOffset() const {
-  if (scroll_clip_layer_id_ == INVALID_ID)
-    return gfx::Vector2d();
-
-  gfx::Size scaled_scroll_bounds(bounds());
-  Layer const* current_layer = this;
-  Layer const* page_scale_layer = layer_tree_host()->page_scale_layer();
-  float scale_factor = 1.f;
-  do {
-    if (current_layer == page_scale_layer) {
-      scale_factor = layer_tree_host()->page_scale_factor();
-      scaled_scroll_bounds.SetSize(
-          scale_factor * scaled_scroll_bounds.width(),
-          scale_factor * scaled_scroll_bounds.height());
-    }
-    current_layer = current_layer->parent();
-  } while (current_layer && current_layer->id() != scroll_clip_layer_id_);
-  DCHECK(current_layer);
-  DCHECK(current_layer->id() == scroll_clip_layer_id_);
-
-  gfx::Vector2dF max_offset(
-      scaled_scroll_bounds.width() - current_layer->bounds().width(),
-      scaled_scroll_bounds.height() - current_layer->bounds().height());
-  // We need the final scroll offset to be in CSS coords.
-  max_offset.Scale(1.f / scale_factor);
-  max_offset.SetToMax(gfx::Vector2dF());
-  return gfx::ToFlooredVector2d(max_offset);
-}
-
 void Layer::SetScrollClipLayerId(int clip_layer_id) {
   DCHECK(IsPropertyChangeAllowed());
   if (scroll_clip_layer_id_ == clip_layer_id)
     return;
   scroll_clip_layer_id_ = clip_layer_id;
   SetNeedsCommit();
 }
 
 void Layer::SetUserScrollable(bool horizontal, bool vertical) {
   DCHECK(IsPropertyChangeAllowed());
@@ skipping 472 matching lines @@
   if (clip_parent_)
     clip_parent_->RemoveClipChild(this);
 
   clip_parent_ = NULL;
 }
 
 void Layer::RunMicroBenchmark(MicroBenchmark* benchmark) {
   benchmark->RunOnLayer(this);
 }
 }  // namespace cc