cc: Reduce surface contents scale adjustments.

cc/trees/property_tree.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 <stddef.h>
 
 #include <set>
 #include <vector>
 
 #include "base/logging.h"
@@ skipping 829 matching lines @@
     return;
   }
 
   TransformTree& transform_tree = property_trees()->transform_tree;
   float layer_scale_factor = transform_tree.device_scale_factor() *
                              transform_tree.device_transform_scale_factor();
   TransformNode* transform_node =
       transform_tree.Node(effect_node->transform_id);
   if (transform_node->in_subtree_of_page_scale_layer)
     layer_scale_factor *= transform_tree.page_scale_factor();
+
+  // Note: Copy requests currently expect transform to effect output size.
+  bool use_transform_for_contents_scale =
+      property_trees()->can_adjust_raster_scales ||
+      effect_node->has_copy_request;
   effect_node->surface_contents_scale =
-      MathUtil::ComputeTransform2dScaleComponents(
-          transform_tree.ToScreen(transform_node->id), layer_scale_factor);
+      use_transform_for_contents_scale
+          ? MathUtil::ComputeTransform2dScaleComponents(
+                transform_tree.ToScreen(transform_node->id), layer_scale_factor)
+          : gfx::Vector2dF(layer_scale_factor, layer_scale_factor);
 }
 
 EffectNode* EffectTree::FindNodeFromElementId(ElementId id) {
   auto iterator = property_trees()->element_id_to_effect_node_index.find(id);
   if (iterator == property_trees()->element_id_to_effect_node_index.end())
     return nullptr;
 
   return Node(iterator->second);
 }
 
@@ skipping 730 matching lines @@
 PropertyTreesCachedData::PropertyTreesCachedData()
     : transform_tree_update_number(0) {
   animation_scales.clear();
 }
 
 PropertyTreesCachedData::~PropertyTreesCachedData() {}
 
 PropertyTrees::PropertyTrees()
     : needs_rebuild(true),
       non_root_surfaces_enabled(true),
+      can_adjust_raster_scales(true),
       changed(false),
       full_tree_damaged(false),
       sequence_number(0),
       is_main_thread(true),
       is_active(false) {
   transform_tree.SetPropertyTrees(this);
   effect_tree.SetPropertyTrees(this);
   clip_tree.SetPropertyTrees(this);
   scroll_tree.SetPropertyTrees(this);
 }
@@ skipping 10 matching lines @@
              other.element_id_to_scroll_node_index &&
          element_id_to_transform_node_index ==
              other.element_id_to_transform_node_index &&
          always_use_active_tree_opacity_effect_ids ==
              other.always_use_active_tree_opacity_effect_ids &&
          needs_rebuild == other.needs_rebuild && changed == other.changed &&
          full_tree_damaged == other.full_tree_damaged &&
          is_main_thread == other.is_main_thread &&
          is_active == other.is_active &&
          non_root_surfaces_enabled == other.non_root_surfaces_enabled &&
+         can_adjust_raster_scales == other.can_adjust_raster_scales &&
          sequence_number == other.sequence_number;
 }
 
 PropertyTrees& PropertyTrees::operator=(const PropertyTrees& from) {
   transform_tree = from.transform_tree;
   effect_tree = from.effect_tree;
   clip_tree = from.clip_tree;
   scroll_tree = from.scroll_tree;
   always_use_active_tree_opacity_effect_ids =
       from.always_use_active_tree_opacity_effect_ids;
   element_id_to_effect_node_index = from.element_id_to_effect_node_index;
   element_id_to_scroll_node_index = from.element_id_to_scroll_node_index;
   element_id_to_transform_node_index = from.element_id_to_transform_node_index;
   needs_rebuild = from.needs_rebuild;
   changed = from.changed;
   full_tree_damaged = from.full_tree_damaged;
   non_root_surfaces_enabled = from.non_root_surfaces_enabled;
+  can_adjust_raster_scales = from.can_adjust_raster_scales;
   sequence_number = from.sequence_number;
   is_main_thread = from.is_main_thread;
   is_active = from.is_active;
   inner_viewport_container_bounds_delta_ =
       from.inner_viewport_container_bounds_delta();
   outer_viewport_container_bounds_delta_ =
       from.outer_viewport_container_bounds_delta();
   inner_viewport_scroll_bounds_delta_ =
       from.inner_viewport_scroll_bounds_delta();
   transform_tree.SetPropertyTrees(this);
@@ skipping 11 matching lines @@
   scroll_tree.clear();
   element_id_to_effect_node_index.clear();
   element_id_to_scroll_node_index.clear();
   element_id_to_transform_node_index.clear();
   always_use_active_tree_opacity_effect_ids.clear();
 
   needs_rebuild = true;
   full_tree_damaged = false;
   changed = false;
   non_root_surfaces_enabled = true;
+  can_adjust_raster_scales = true;
   sequence_number++;
 
 #if DCHECK_IS_ON()
   PropertyTrees tree;
   tree.transform_tree = transform_tree;
   tree.effect_tree = effect_tree;
   tree.clip_tree = clip_tree;
   tree.scroll_tree = scroll_tree;
   tree.scroll_tree.CopyCompleteTreeState(scroll_tree);
 
@@ skipping 430 matching lines @@
   const EffectNode* effect_node = effect_tree.Node(effect_id);
 
   if (effect_node->surface_contents_scale.x() != 0.0 &&
       effect_node->surface_contents_scale.y() != 0.0)
     screen_space_transform.Scale(1.0 / effect_node->surface_contents_scale.x(),
                                  1.0 / effect_node->surface_contents_scale.y());
   return screen_space_transform;
 }
 
 }  // namespace cc