[SPv2] Implement CSS clip property

third_party/WebKit/Source/platform/graphics/compositing/PaintArtifactCompositor.cpp

 // Copyright 2015 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 "platform/graphics/compositing/PaintArtifactCompositor.h"
 
 #include "cc/layers/content_layer_client.h"
 #include "cc/layers/layer.h"
 #include "cc/layers/picture_layer.h"
 #include "cc/playback/display_item_list.h"
@@ skipping 155 matching lines @@
 {
     // TODO(jbroman): Handle rounded-rect clips.
     // TODO(jbroman): Handle clips of non-integer size.
     gfx::RectF clipRect = node->clipRect().rect();
 
     // TODO(jbroman): This, and the similar logic in
     // PaintArtifactCompositor::update, will need to be updated to account for
     // other kinds of intermediate layers, such as those that apply effects.
     // TODO(jbroman): This assumes that the transform space of this node's
     // parent is an ancestor of this node's transform space. That's not
-    // necessarily true, and this should be fixed.
+    // necessarily true, and this should be fixed. crbug.com/597156
     gfx::Transform transform = transformToTransformSpace(localTransformSpace(node), localTransformSpace(node->parent()));
     gfx::Vector2dF offset = clipRect.OffsetFromOrigin();
     transform.Translate(offset.x(), offset.y());
     if (node->parent()) {
         FloatPoint offsetDueToParentClipOffset = node->parent()->clipRect().rect().location();
         gfx::Transform undoClipOffset;
         undoClipOffset.Translate(-offsetDueToParentClipOffset.x(), -offsetDueToParentClipOffset.y());
         transform.ConcatTransform(undoClipOffset);
     }
 
@@ skipping 77 matching lines @@
     ASSERT(m_rootLayer);
 
     // TODO(jbroman): This should be incremental.
     m_rootLayer->RemoveAllChildren();
     m_contentLayerClients.clear();
 
     m_contentLayerClients.reserveCapacity(paintArtifact.paintChunks().size());
     ClipLayerManager clipLayerManager(m_rootLayer.get());
     for (const PaintChunk& paintChunk : paintArtifact.paintChunks()) {
         cc::Layer* parent = clipLayerManager.switchToNewClipLayer(paintChunk.properties.clip.get());
+        // TODO(jbroman): Same as above. This assumes the transform space of the current clip is
+        // an ancestor of the chunk. It is not necessarily true. crbug.com/597156
         gfx::Transform transform = transformToTransformSpace(paintChunk.properties.transform.get(), localTransformSpace(paintChunk.properties.clip.get()));
         scoped_refptr<cc::Layer> layer = layerForPaintChunk(paintArtifact, paintChunk, transform);
         layer->SetNeedsDisplay();
         parent->AddChild(std::move(layer));
     }
 }
 
 scoped_refptr<cc::Layer> PaintArtifactCompositor::layerForPaintChunk(const PaintArtifact& paintArtifact, const PaintChunk& paintChunk, gfx::Transform transform)
 {
     // If the paint chunk is a foreign layer, just return that layer.
@@ skipping 27 matching lines @@
     layer->SetIsDrawable(true);
     layer->SetDoubleSided(!paintChunk.properties.backfaceHidden);
     if (paintChunk.knownToBeOpaque)
         layer->SetContentsOpaque(true);
     m_contentLayerClients.append(contentLayerClient.release());
     return layer;
 }
 
 
 } // namespace blink