Plumb CompositingReason from Blink to compositor.

Source/core/rendering/RenderLayerBacking.cpp

 /*
  * Copyright (C) 2009, 2010, 2011 Apple Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  * 1. Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
  * 2. Redistributions in binary form must reproduce the above copyright
  *    notice, this list of conditions and the following disclaimer in the
@@ skipping 32 matching lines @@
 #include "core/page/animation/AnimationController.h"
 #include "core/page/scrolling/ScrollingCoordinator.h"
 #include "core/platform/graphics/FontCache.h"
 #include "core/platform/graphics/GraphicsContext.h"
 #include "core/platform/graphics/GraphicsLayer.h"
 #include "core/plugins/PluginView.h"
 #include "core/rendering/RenderApplet.h"
 #include "core/rendering/RenderEmbeddedObject.h"
 #include "core/rendering/RenderIFrame.h"
 #include "core/rendering/RenderImage.h"
+#include "core/rendering/RenderLayer.h" // FIXME - only needed for CompositingReasons, see if we can move that to a better home.

[jamesr, 2013/05/17 00:10:20]

RenderLayerBacking reaches into RenderLayers all over the place, I think this
#include is fine. I'd remove the FIXME

 #include "core/rendering/RenderLayerCompositor.h"
 #include "core/rendering/RenderVideo.h"
 #include "core/rendering/RenderView.h"
 #include "core/rendering/style/KeyframeList.h"
 #include <wtf/CurrentTime.h>
 #include <wtf/text/StringBuilder.h>
 
 #include "core/platform/graphics/filters/custom/CustomFilterOperation.h"
 #include "core/rendering/FilterEffectRenderer.h"
 
@@ skipping 276 matching lines @@
 void RenderLayerBacking::updateAfterWidgetResize()
 {
     if (renderer()->isRenderPart()) {
         if (RenderLayerCompositor* innerCompositor = RenderLayerCompositor::frameContentsCompositor(toRenderPart(renderer()))) {
             innerCompositor->frameViewDidChangeSize();
             innerCompositor->frameViewDidChangeLocation(contentsBox().location());
         }
     }
 }
 
+void RenderLayerBacking::updateCompositingReasons()
+{
+    m_graphicsLayer->setCompositingReasons(m_owningLayer->compositingReasons());
+
+    if (m_ancestorClippingLayer)
+        m_ancestorClippingLayer->setCompositingReasons(CompositingReasonLayerForClip);
+
+    if (m_contentsContainmentLayer)
+        m_contentsContainmentLayer->setCompositingReasons(CompositingReasonNone);
+
+    if (m_foregroundLayer)
+        m_foregroundLayer->setCompositingReasons(CompositingReasonsLayerForForeground);
+
+    if (m_backgroundLayer)
+        m_backgroundLayer->setCompositingReasons(CompositingReasonNone);
+
+    if (m_childContainmentLayer)
+        m_childContainmentLayer->setCompositingReasons(CompositingReasonNone);
+
+    if (m_maskLayer)
+        m_maskLayer->setCompositingReasons(CompositingReasonNone);
+
+    if (m_layerForHorizontalScrollbar)
+        m_layerForHorizontalScrollbar->setCompositingReasons(CompositingReasonLayerForScrollbar);
+
+    if (m_layerForVerticalScrollbar)
+        m_layerForVerticalScrollbar->setCompositingReasons(CompositingReasonLayerForScrollbar);
+
+    if (m_layerForScrollCorner)
+        m_layerForScrollCorner->setCompositingReasons(CompositingReasonLayerForScrollbar);
+
+    // Is this the correct reason?
+    if (m_scrollingLayer)
+        m_scrollingLayer->setCompositingReasons(CompositingReasonLayerForDescendantClip);
+
+    if (m_scrollingContentsLayer)
+        m_scrollingContentsLayer->setCompositingReasons(CompositingReasonsLayerForScrollingContainer);
+}
+
 void RenderLayerBacking::updateAfterLayout(UpdateAfterLayoutFlags flags)
 {
     RenderLayerCompositor* layerCompositor = compositor();
     if (!layerCompositor->compositingLayersNeedRebuild()) {
         // Calling updateGraphicsLayerGeometry() here gives incorrect results, because the
         // position of this layer's GraphicsLayer depends on the position of our compositing
         // ancestor's GraphicsLayer. That cannot be determined until all the descendant 
         // RenderLayers of that ancestor have been processed via updateLayerPositions().
         //
         // The solution is to update compositing children of this layer here,
@@ skipping 352 matching lines @@
     }
 
     // If this layer was created just for clipping or to apply perspective, it doesn't need its own backing store.
     setRequiresOwnBackingStore(compositor()->requiresOwnBackingStore(m_owningLayer, compAncestor));
 
     updateContentsRect(isSimpleContainer);
     updateBackgroundColor(isSimpleContainer);
     updateDrawsContent(isSimpleContainer);
     updateAfterWidgetResize();
     registerScrollingLayers();
+
+    updateCompositingReasons();
 }
 
 void RenderLayerBacking::registerScrollingLayers()
 {
     // Register fixed position layers and their containers with the scrolling coordinator.
     ScrollingCoordinator* scrollingCoordinator = scrollingCoordinatorFromLayer(m_owningLayer);
     if (!scrollingCoordinator)
         return;
 
     compositor()->updateViewportConstraintStatus(m_owningLayer);
@@ skipping 1224 matching lines @@
     info.addMember(m_childContainmentLayer, "childContainmentLayer");
     info.addMember(m_maskLayer, "maskLayer");
     info.addMember(m_layerForHorizontalScrollbar, "layerForHorizontalScrollbar");
     info.addMember(m_layerForVerticalScrollbar, "layerForVerticalScrollbar");
     info.addMember(m_layerForScrollCorner, "layerForScrollCorner");
     info.addMember(m_scrollingLayer, "scrollingLayer");
     info.addMember(m_scrollingContentsLayer, "scrollingContentsLayer");
 }
 
 } // namespace WebCore