cc: Clip delegated quads to the correct clip rect.

cc/layer_tree_host_common.cc

 // Copyright 2011 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/layer_tree_host_common.h"
 
 #include <algorithm>
 
 #include "base/debug/trace_event.h"
 #include "cc/layer.h"
@@ skipping 114 matching lines @@
         return layer->transform().IsBackFaceVisible();
 
     // If the renderSurface is not part of a new or existing rendering context, then the
     // layers that contribute to this surface will decide back-face visibility for themselves.
     return false;
 }
 
 template<typename LayerType>
 static inline bool layerClipsSubtree(LayerType* layer)
 {
-    return layer->masksToBounds() || layer->maskLayer() || layer->hasDelegatedContent();
+    return layer->masksToBounds() || layer->maskLayer();
 }
 
 template<typename LayerType>
 static gfx::Rect calculateVisibleContentRect(LayerType* layer, const gfx::Rect& ancestorClipRectInDescendantSurfaceSpace, const gfx::Rect& layerRectInTargetSpace)
 {
     DCHECK(layer->renderTarget());
 
     // Nothing is visible if the layer bounds are empty.
     if (!layer->drawsContent() || layer->contentBounds().IsEmpty() || layer->drawableContentRect().IsEmpty())
         return gfx::Rect();
@@ skipping 138 matching lines @@
     int numDescendantsThatDrawContent = layer->drawProperties().num_descendants_that_draw_content;
 
     // If the layer flattens its subtree (i.e. the layer doesn't preserve-3d), but it is
     // treated as a 3D object by its parent (i.e. parent does preserve-3d).
     if (layerIsInExisting3DRenderingContext(layer) && !layer->preserves3D() && numDescendantsThatDrawContent > 0) {
         TRACE_EVENT_INSTANT0("cc", "LayerTreeHostCommon::requireSurface flattening");
         return true;
     }
 
     // If the layer clips its descendants but it is not axis-aligned with respect to its parent.
-    if (layerClipsSubtree(layer) && !axisAlignedWithRespectToParent && !layer->drawProperties().descendants_can_clip_selves)
+    bool layerClipsExternalContent = layerClipsSubtree(layer) || layer->hasDelegatedContent();
+    if (layerClipsExternalContent && !axisAlignedWithRespectToParent && !layer->drawProperties().descendants_can_clip_selves)
     {
         TRACE_EVENT_INSTANT0("cc", "LayerTreeHostCommon::requireSurface clipping");
         return true;
     }
 
     // If the layer has some translucency and does not have a preserves-3d transform style.
     // This condition only needs a render surface if two or more layers in the
     // subtree overlap. But checking layer overlaps is unnecessarily costly so
     // instead we conservatively create a surface whenever at least two layers
     // draw content for this subtree.
@@ skipping 877 matching lines @@
 
   // At this point, we think the point does hit the touch event handler region on the layer, but we need to walk up
   // the parents to ensure that the layer was not clipped in such a way that the
   // hit point actually should not hit the layer.
   if (pointIsClippedBySurfaceOrClipRect(screenSpacePoint, layerImpl))
      return false;
 
   return true;
 }
 }  // namespace cc