Implements core logic for Pixel Canvas

ui/compositor/layer.cc

 // Copyright (c) 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 "ui/compositor/layer.h"
 
 #include <algorithm>
 #include <memory>
 #include <utility>
 
@@ skipping 22 matching lines @@
 #include "ui/gfx/canvas.h"
 #include "ui/gfx/geometry/dip_util.h"
 #include "ui/gfx/geometry/point3_f.h"
 #include "ui/gfx/geometry/point_conversions.h"
 #include "ui/gfx/geometry/size_conversions.h"
 #include "ui/gfx/interpolated_transform.h"
 
 namespace {
 
 const ui::Layer* GetRoot(const ui::Layer* layer) {
+  // Parent walk cannot be done on a layer that is being used as a mask. Get the
+  // layer to which this layer is a mask of.
+  if (layer->layer_mask_back_link())
+    layer = layer->layer_mask_back_link();
   while (layer->parent())
     layer = layer->parent();
   return layer;
 }
 
 }  // namespace
 
 namespace ui {
 
 class Layer::LayerMirror : public LayerDelegate, LayerObserver {
@@ skipping 385 matching lines @@
   }
   return layer_grayscale();
 }
 
 void Layer::SetLayerInverted(bool inverted) {
   layer_inverted_ = inverted;
   SetLayerFilters();
 }
 
 void Layer::SetMaskLayer(Layer* layer_mask) {
   if (layer_mask_ == layer_mask)

[danakj, 2017/07/26 16:06:04]

usually nice to keep DCHECKs at the top of the function. is there a reason this
moved?

[malaykeshav, 2017/07/26 18:34:45]

This modification is not a part of this CL. 
https://chromium-review.googlesource.com/#/c/578232/

     return;
   // The provided mask should not have a layer mask itself.
   DCHECK(!layer_mask ||
          (!layer_mask->layer_mask_layer() && layer_mask->children().empty() &&
           !layer_mask->layer_mask_back_link_));
   DCHECK(!layer_mask_back_link_);
   // We need to de-reference the currently linked object so that no problem
   // arises if the mask layer gets deleted before this object.
   if (layer_mask_)
     layer_mask_->layer_mask_back_link_ = NULL;
@@ skipping 467 matching lines @@
 
 scoped_refptr<cc::DisplayItemList> Layer::PaintContentsToDisplayList(
     ContentLayerClient::PaintingControlSetting painting_control) {
   TRACE_EVENT1("ui", "Layer::PaintContentsToDisplayList", "name", name_);
   gfx::Rect local_bounds(bounds().size());
   gfx::Rect invalidation(
       gfx::IntersectRects(paint_region_.bounds(), local_bounds));
   paint_region_.Clear();
   auto display_list = make_scoped_refptr(new cc::DisplayItemList);
   if (delegate_) {
-    delegate_->OnPaintLayer(
-        PaintContext(display_list.get(), device_scale_factor_, invalidation));
+    delegate_->OnPaintLayer(PaintContext(display_list.get(),
+                                         device_scale_factor_, invalidation,
+                                         GetCompositor()->is_pixel_canvas()));
   }
   display_list->Finalize();
   // TODO(domlaskowski): Move mirror invalidation to Layer::SchedulePaint.
   for (const auto& mirror : mirrors_)
     mirror->dest()->SchedulePaint(invalidation);
   return display_list;
 }
 
 bool Layer::FillsBoundsCompletely() const { return fills_bounds_completely_; }
 
@@ skipping 306 matching lines @@
   const auto it = std::find_if(mirrors_.begin(), mirrors_.end(),
       [mirror](const std::unique_ptr<LayerMirror>& mirror_ptr) {
         return mirror_ptr.get() == mirror;
       });
 
   DCHECK(it != mirrors_.end());
   mirrors_.erase(it);
 }
 
 }  // namespace ui