Suppress layer creation for descendants of GPU-rasterized layers

Source/core/rendering/RenderLayer.cpp

 /*
  * Copyright (C) 2006, 2007, 2008, 2009, 2010, 2011, 2012 Apple Inc. All rights reserved.
  *
  * Portions are Copyright (C) 1998 Netscape Communications Corporation.
  *
  * Other contributors:
  *   Robert O'Callahan <roc+@cs.cmu.edu>
  *   David Baron <dbaron@fas.harvard.edu>
  *   Christian Biesinger <cbiesinger@web.de>
  *   Randall Jesup <rjesup@wgate.com>
@@ skipping 787 matching lines @@
 {
     TRACE_EVENT0("blink_rendering", "RenderLayer::updateScrollingStateAfterCompositingChange");
     m_hasVisibleNonLayerContent = false;
     for (RenderObject* r = renderer()->firstChild(); r; r = r->nextSibling()) {
         if (!r->hasLayer()) {
             m_hasVisibleNonLayerContent = true;
             break;
         }
     }
 
-    m_compositingProperties.hasNonCompositedChild = false;
+    compositingProperties().hasNonCompositedChild = false;
     for (RenderLayer* child = firstChild(); child; child = child->nextSibling()) {
         if (child->compositingState() == NotComposited) {
-            m_compositingProperties.hasNonCompositedChild = true;
+            compositingProperties().hasNonCompositedChild = true;
             return;
         }
     }
 }
 
 static bool subtreeContainsOutOfFlowPositionedLayer(const RenderLayer* subtreeRoot)
 {
     return (subtreeRoot->renderer() && subtreeRoot->renderer()->isOutOfFlowPositioned()) || subtreeRoot->hasOutOfFlowPositionedDescendant();
 }
 
@@ skipping 374 matching lines @@
 
 void RenderLayer::clearChildNeedsToUpdateAncestorDependantProperties()
 {
     ASSERT(!m_needsToUpdateAncestorDependentProperties);
     m_childNeedsToUpdateAncestorDependantProperties = false;
 }
 
 void RenderLayer::setCompositingReasons(CompositingReasons reasons, CompositingReasons mask)
 {
     ASSERT(reasons == (reasons & mask));
-    if ((m_compositingProperties.compositingReasons & mask) == (reasons & mask))
+    if ((compositingProperties().compositingReasons & mask) == (reasons & mask))
         return;

[abarth-chromium, 2014/04/17 17:29:51]

This mask argument might not be needed anymore now that we store the
style-determined reasons separately.

[ajuma, 2014/04/17 19:24:44]

RenderLayerCompositor::updateDirectCompositingReasons calls this with mask
CompositingReasonComboAllDirectReasons, so we still need the mask argument for
now.

-    m_compositingProperties.compositingReasons = (reasons & mask) | (m_compositingProperties.compositingReasons & ~mask);
+    compositingProperties().compositingReasons = (reasons & mask) | (compositingProperties().compositingReasons & ~mask);
     m_clipper.setCompositingClipRectsDirty();
 }
 
 bool RenderLayer::hasAncestorWithFilterOutsets() const
 {
     for (const RenderLayer* curr = this; curr; curr = curr->parent()) {
         RenderLayerModelObject* renderer = curr->renderer();
         if (renderer->style()->hasFilterOutsets())
             return true;
     }
@@ skipping 2828 matching lines @@
     }
 }
 
 void showLayerTree(const WebCore::RenderObject* renderer)
 {
     if (!renderer)
         return;
     showLayerTree(renderer->enclosingLayer());
 }
 #endif