Plumb preferred raster scale for background images from Blink to cc layers.

cc/layers/layer_impl.cc

 // Copyright 2012 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_impl.h"
 
 #include <stddef.h>
 #include <stdint.h>
 
 #include <algorithm>
@@ skipping 61 matching lines @@
       safe_opaque_background_color_(0),
       draw_blend_mode_(SkXfermode::kSrcOver_Mode),
       transform_tree_index_(TransformTree::kInvalidNodeId),
       effect_tree_index_(EffectTree::kInvalidNodeId),
       clip_tree_index_(ClipTree::kInvalidNodeId),
       scroll_tree_index_(ScrollTree::kInvalidNodeId),
       sorting_context_id_(0),
       current_draw_mode_(DRAW_MODE_NONE),
       mutable_properties_(MutableProperty::kNone),
       debug_info_(nullptr),
+      preferred_raster_scale_(1.0f),
+      has_preferred_raster_scale_(false),
       scrolls_drawn_descendant_(false),
       has_will_change_transform_hint_(false),
       needs_push_properties_(false) {
   DCHECK_GT(layer_id_, 0);
 
   DCHECK(layer_tree_impl_);
   layer_tree_impl_->RegisterLayer(this);
   layer_tree_impl_->AddToElementMap(this);
 
   SetNeedsPushProperties();
 }
 
 LayerImpl::~LayerImpl() {
   DCHECK_EQ(DRAW_MODE_NONE, current_draw_mode_);
 
   layer_tree_impl_->UnregisterScrollLayer(this);
   layer_tree_impl_->UnregisterLayer(this);
 
   layer_tree_impl_->RemoveFromElementMap(this);
 
   TRACE_EVENT_OBJECT_DELETED_WITH_ID(
       TRACE_DISABLED_BY_DEFAULT("cc.debug"), "cc::LayerImpl", this);
 }
 
 void LayerImpl::SetHasWillChangeTransformHint(bool has_will_change) {
   has_will_change_transform_hint_ = has_will_change;
 }
 
+void LayerImpl::SetPreferredRasterScale(float preferred_raster_scale) {
+  has_preferred_raster_scale_ = true;
+  preferred_raster_scale_ = preferred_raster_scale;
+}
+
+void LayerImpl::ClearPreferredRasterScale() {
+  has_preferred_raster_scale_ = false;
+  preferred_raster_scale_ = 1.0f;
+}
+
 AnimationHost* LayerImpl::GetAnimationHost() const {
   return layer_tree_impl_ ? layer_tree_impl_->animation_host() : nullptr;
 }
 
 ElementListType LayerImpl::GetElementTypeForAnimation() const {
   return IsActive() ? ElementListType::ACTIVE : ElementListType::PENDING;
 }
 
 void LayerImpl::SetDebugInfo(
     std::unique_ptr<base::trace_event::ConvertableToTraceFormat> debug_info) {
@@ skipping 961 matching lines @@
            .layer_transforms_should_scale_layer_contents) {
     return default_scale;
   }
 
   gfx::Vector2dF transform_scales = MathUtil::ComputeTransform2dScaleComponents(
       ScreenSpaceTransform(), default_scale);
   return std::max(transform_scales.x(), transform_scales.y());
 }
 
 }  // namespace cc