cc : Delete layer's draw blend mode

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 52 matching lines @@
       masks_to_bounds_(false),
       contents_opaque_(false),
       use_parent_backface_visibility_(false),
       use_local_transform_for_backface_visibility_(false),
       should_check_backface_visibility_(false),
       draws_content_(false),
       is_drawn_render_surface_layer_list_member_(false),
       was_ever_ready_since_last_transform_animation_(true),
       background_color_(0),
       safe_opaque_background_color_(0),
-      draw_blend_mode_(SkBlendMode::kSrcOver),
       transform_tree_index_(TransformTree::kInvalidNodeId),
       effect_tree_index_(EffectTree::kInvalidNodeId),
       clip_tree_index_(ClipTree::kInvalidNodeId),
       scroll_tree_index_(ScrollTree::kInvalidNodeId),
       current_draw_mode_(DRAW_MODE_NONE),
       mutable_properties_(MutableProperty::kNone),
       debug_info_(nullptr),
       has_will_change_transform_hint_(false),
       needs_push_properties_(false),
       scrollbars_hidden_(false),
@@ skipping 60 matching lines @@
 }
 
 void LayerImpl::SetScrollTreeIndex(int index) {
   scroll_tree_index_ = index;
 }
 
 void LayerImpl::PopulateSharedQuadState(SharedQuadState* state) const {
   state->SetAll(draw_properties_.target_space_transform, bounds(),
                 draw_properties_.visible_layer_rect, draw_properties_.clip_rect,
                 draw_properties_.is_clipped, draw_properties_.opacity,
-                draw_blend_mode_, GetSortingContextId());
+                SkBlendMode::kSrcOver, GetSortingContextId());
 }
 
 void LayerImpl::PopulateScaledSharedQuadState(
     SharedQuadState* state,
     float layer_to_content_scale_x,
     float layer_to_content_scale_y) const {
   gfx::Transform scaled_draw_transform =
       draw_properties_.target_space_transform;
   scaled_draw_transform.Scale(SK_MScalar1 / layer_to_content_scale_x,
                               SK_MScalar1 / layer_to_content_scale_y);
   gfx::Size scaled_bounds = gfx::ScaleToCeiledSize(
       bounds(), layer_to_content_scale_x, layer_to_content_scale_y);
   gfx::Rect scaled_visible_layer_rect = gfx::ScaleToEnclosingRect(
       visible_layer_rect(), layer_to_content_scale_x, layer_to_content_scale_y);
   scaled_visible_layer_rect.Intersect(gfx::Rect(scaled_bounds));
 
   state->SetAll(scaled_draw_transform, scaled_bounds, scaled_visible_layer_rect,
                 draw_properties().clip_rect, draw_properties().is_clipped,
-                draw_properties().opacity, draw_blend_mode_,
+                draw_properties().opacity, SkBlendMode::kSrcOver,

[weiliangc, 2017/04/10 15:42:20]

Do we ever set SharedQuadState's blend mode to anything other than kSrcOver? Can
we delete the draw blend mode in shared quad state too?

[jaydasika, 2017/04/10 16:29:33]

We can set it to something other than kSrcOver when its called by
RenderSurfaceImpl instead of LayerImpl.

                 GetSortingContextId());
 }
 
 bool LayerImpl::WillDraw(DrawMode draw_mode,
                          ResourceProvider* resource_provider) {
   // WillDraw/DidDraw must be matched.
   DCHECK_NE(DRAW_MODE_NONE, draw_mode);
   DCHECK_EQ(DRAW_MODE_NONE, current_draw_mode_);
   current_draw_mode_ = draw_mode;
   return true;
@@ skipping 140 matching lines @@
   layer->may_contain_video_ = may_contain_video_;
   layer->use_parent_backface_visibility_ = use_parent_backface_visibility_;
   layer->use_local_transform_for_backface_visibility_ =
       use_local_transform_for_backface_visibility_;
   layer->should_check_backface_visibility_ = should_check_backface_visibility_;
   layer->draws_content_ = draws_content_;
   layer->non_fast_scrollable_region_ = non_fast_scrollable_region_;
   layer->touch_event_handler_region_ = touch_event_handler_region_;
   layer->background_color_ = background_color_;
   layer->safe_opaque_background_color_ = safe_opaque_background_color_;
-  layer->draw_blend_mode_ = draw_blend_mode_;
   layer->position_ = position_;
   layer->transform_tree_index_ = transform_tree_index_;
   layer->effect_tree_index_ = effect_tree_index_;
   layer->clip_tree_index_ = clip_tree_index_;
   layer->scroll_tree_index_ = scroll_tree_index_;
   layer->has_will_change_transform_hint_ = has_will_change_transform_hint_;
   layer->scrollbars_hidden_ = scrollbars_hidden_;
   layer->needs_show_scrollbars_ = needs_show_scrollbars_;
 
   if (layer_property_changed_) {
@@ skipping 631 matching lines @@
 
 ScrollTree& LayerImpl::GetScrollTree() const {
   return GetPropertyTrees()->scroll_tree;
 }
 
 TransformTree& LayerImpl::GetTransformTree() const {
   return GetPropertyTrees()->transform_tree;
 }
 
 }  // namespace cc