Implement will-change-based GPU rasterization hint

Source/platform/graphics/GraphicsLayer.cpp

 /*
  * Copyright (C) 2009 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 71 matching lines @@
     , m_opacity(1)
     , m_zPosition(0)
     , m_blendMode(blink::WebBlendModeNormal)
     , m_contentsOpaque(false)
     , m_shouldFlattenTransform(true)
     , m_backfaceVisibility(true)
     , m_masksToBounds(false)
     , m_drawsContent(false)
     , m_contentsVisible(true)
     , m_isRootForIsolatedGroup(false)
+    , m_hasGpuRasterizationHint(false)
     , m_hasScrollParent(false)
     , m_hasClipParent(false)
     , m_paintingPhase(GraphicsLayerPaintAllWithOverflowClip)
     , m_contentsOrientation(CompositingCoordinatesTopDown)
     , m_parent(0)
     , m_maskLayer(0)
     , m_contentsClippingMaskLayer(0)
     , m_replicaLayer(0)
     , m_replicatedLayer(0)
     , m_paintCount(0)
@@ skipping 498 matching lines @@
     if (m_drawsContent) {
         writeIndent(ts, indent + 1);
         ts << "(drawsContent " << m_drawsContent << ")\n";
     }
 
     if (!m_contentsVisible) {
         writeIndent(ts, indent + 1);
         ts << "(contentsVisible " << m_contentsVisible << ")\n";
     }
 
+    if (m_hasGpuRasterizationHint) {
+        writeIndent(ts, indent + 1);
+        ts << "(hasGpuRasterizationHint " << m_hasGpuRasterizationHint << ")\n";
+    }
+
     if (!m_backfaceVisibility) {
         writeIndent(ts, indent + 1);
         ts << "(backfaceVisibility " << (m_backfaceVisibility ? "visible" : "hidden") << ")\n";
     }
 
     if (flags & LayerTreeIncludesDebugInfo) {
         writeIndent(ts, indent + 1);
         ts << "(";
         if (m_client)
             ts << "client " << static_cast<void*>(m_client);
@@ skipping 319 matching lines @@
 }
 
 void GraphicsLayer::setIsRootForIsolatedGroup(bool isolated)
 {
     if (m_isRootForIsolatedGroup == isolated)
         return;
     m_isRootForIsolatedGroup = isolated;
     platformLayer()->setIsRootForIsolatedGroup(isolated);
 }
 
+void GraphicsLayer::setHasGpuRasterizationHint(bool hasHint)
+{
+    m_hasGpuRasterizationHint = hasHint;
+    m_layer->setHasGpuRasterizationHint(hasHint);
+}
+
 void GraphicsLayer::setContentsNeedsDisplay()
 {
     if (WebLayer* contentsLayer = contentsLayerIfRegistered()) {
         contentsLayer->invalidate();
         addRepaintRect(contentsRect());
     }
 }
 
 void GraphicsLayer::setNeedsDisplay()
 {
@@ skipping 245 matching lines @@
 #ifndef NDEBUG
 void showGraphicsLayerTree(const WebCore::GraphicsLayer* layer)
 {
     if (!layer)
         return;
 
     String output = layer->layerTreeAsText(WebCore::LayerTreeIncludesDebugInfo);
     fprintf(stderr, "%s\n", output.utf8().data());
 }
 #endif