Remove parts of //cc we aren't using

cc/input/scroll_elasticity_helper.cc

-// Copyright 2014 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/input/scroll_elasticity_helper.h"
-
-#include "cc/layers/layer_impl.h"
-#include "cc/trees/layer_tree_host_impl.h"
-#include "cc/trees/layer_tree_impl.h"
-
-namespace cc {
-
-class ScrollElasticityHelperImpl : public ScrollElasticityHelper {
- public:
-  explicit ScrollElasticityHelperImpl(LayerTreeHostImpl* layer_tree_host_impl);
-  ~ScrollElasticityHelperImpl() override;
-
-  bool IsUserScrollable() const override;
-  gfx::Vector2dF StretchAmount() const override;
-  void SetStretchAmount(const gfx::Vector2dF& stretch_amount) override;
-  gfx::ScrollOffset ScrollOffset() const override;
-  gfx::ScrollOffset MaxScrollOffset() const override;
-  void ScrollBy(const gfx::Vector2dF& delta) override;
-  void RequestAnimate() override;
-
- private:
-  LayerTreeHostImpl* layer_tree_host_impl_;
-};
-
-ScrollElasticityHelperImpl::ScrollElasticityHelperImpl(
-    LayerTreeHostImpl* layer_tree)
-    : layer_tree_host_impl_(layer_tree) {
-}
-
-ScrollElasticityHelperImpl::~ScrollElasticityHelperImpl() {
-}
-
-bool ScrollElasticityHelperImpl::IsUserScrollable() const {
-  LayerImpl* layer = layer_tree_host_impl_->OuterViewportScrollLayer();
-  if (!layer)
-    return false;
-  return layer->user_scrollable_horizontal() ||
-         layer->user_scrollable_vertical();
-}
-
-gfx::Vector2dF ScrollElasticityHelperImpl::StretchAmount() const {
-  return layer_tree_host_impl_->active_tree()->elastic_overscroll()->Current(
-      true);
-}
-
-void ScrollElasticityHelperImpl::SetStretchAmount(
-    const gfx::Vector2dF& stretch_amount) {
-  if (stretch_amount == StretchAmount())
-    return;
-
-  layer_tree_host_impl_->active_tree()->elastic_overscroll()->SetCurrent(
-      stretch_amount);
-  layer_tree_host_impl_->active_tree()->set_needs_update_draw_properties();
-  layer_tree_host_impl_->SetNeedsCommit();
-  layer_tree_host_impl_->SetNeedsRedraw();
-  layer_tree_host_impl_->SetFullRootLayerDamage();
-}
-
-gfx::ScrollOffset ScrollElasticityHelperImpl::ScrollOffset() const {
-  return layer_tree_host_impl_->active_tree()->TotalScrollOffset();
-}
-
-gfx::ScrollOffset ScrollElasticityHelperImpl::MaxScrollOffset() const {
-  return layer_tree_host_impl_->active_tree()->TotalMaxScrollOffset();
-}
-
-void ScrollElasticityHelperImpl::ScrollBy(const gfx::Vector2dF& delta) {
-  LayerImpl* root_scroll_layer =
-      layer_tree_host_impl_->OuterViewportScrollLayer()
-          ? layer_tree_host_impl_->OuterViewportScrollLayer()
-          : layer_tree_host_impl_->InnerViewportScrollLayer();
-  if (root_scroll_layer)
-    root_scroll_layer->ScrollBy(delta);
-}
-
-void ScrollElasticityHelperImpl::RequestAnimate() {
-  layer_tree_host_impl_->SetNeedsAnimate();
-}
-
-// static
-ScrollElasticityHelper* ScrollElasticityHelper::CreateForLayerTreeHostImpl(
-    LayerTreeHostImpl* layer_tree_host_impl) {
-  return new ScrollElasticityHelperImpl(layer_tree_host_impl);
-}
-
-}  // namespace cc