Add tests and settings plumbing for accelerated fixed root background

Source/core/rendering/RenderLayerCompositor.cpp

 /*
  * Copyright (C) 2009, 2010 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 31 matching lines @@
 #include "core/page/Page.h"
 #include "core/page/Settings.h"
 #include "core/page/animation/AnimationController.h"
 #include "core/page/scrolling/ScrollingConstraints.h"
 #include "core/page/scrolling/ScrollingCoordinator.h"
 #include "core/platform/HistogramSupport.h"
 #include "core/platform/Logging.h"
 #include "core/platform/ScrollbarTheme.h"
 #include "core/platform/chromium/TraceEvent.h"
 #include "core/platform/graphics/GraphicsLayer.h"
+#include "core/platform/graphics/GraphicsLayerClient.h"
 #include "core/platform/graphics/transforms/TransformState.h"
 #include "core/rendering/HitTestResult.h"
 #include "core/rendering/RenderApplet.h"
 #include "core/rendering/RenderEmbeddedObject.h"
 #include "core/rendering/RenderFullScreen.h"
 #include "core/rendering/RenderGeometryMap.h"
 #include "core/rendering/RenderIFrame.h"
 #include "core/rendering/RenderLayerBacking.h"
 #include "core/rendering/RenderReplica.h"
 #include "core/rendering/RenderVideo.h"
@@ skipping 1143 matching lines @@
 }
 
 String RenderLayerCompositor::layerTreeAsText(LayerTreeFlags flags)
 {
     updateCompositingLayers(CompositingUpdateAfterLayout);
 
     if (!m_rootContentLayer)
         return String();
 
     // We skip dumping the scroll and clip layers to keep layerTreeAsText output
-    // similar between platforms.
-    String layerTreeText = m_rootContentLayer->layerTreeAsText(flags);
+    // similar between platforms (unless we explicitly request dumping from the
+    // root.
+    GraphicsLayer* rootLayer = m_rootContentLayer.get();
+    if (flags & LayerTreeIncludesRootLayer)
+        rootLayer = rootGraphicsLayer();
+
+    String layerTreeText = rootLayer->layerTreeAsText(flags);
 
     // The true root layer is not included in the dump, so if we want to report
     // its repaint rects, they must be included here.
     if (flags & LayerTreeIncludesRepaintRects) {
         String layerTreeTextWithRootRepaintRects = m_renderView->frameView()->trackedRepaintRectsAsText();
         layerTreeTextWithRootRepaintRects.append(layerTreeText);
         return layerTreeTextWithRootRepaintRects;
     }
 
     return layerTreeText;
@@ skipping 1504 matching lines @@
     info.addMember(m_layerForScrollCorner, "layerForScrollCorner");
 #if ENABLE(RUBBER_BANDING)
     info.addMember(m_layerForOverhangAreas, "layerForOverhangAreas");
     info.addMember(m_contentShadowLayer, "contentShadowLayer");
     info.addMember(m_layerForTopOverhangArea, "layerForTopOverhangArea");
     info.addMember(m_layerForBottomOverhangArea, "layerForBottomOverhangArea");
 #endif
 }
 
 } // namespace WebCore