Implement interest rects for synchronized paint.

third_party/WebKit/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 274 matching lines @@
     if (offset == m_offsetFromLayoutObject)
         return;
 
     m_offsetFromLayoutObject = offset;
 
     // If the compositing layer offset changes, we need to repaint.
     if (shouldSetNeedsDisplay == SetNeedsDisplay)
         setNeedsDisplay();
 }
 
-void GraphicsLayer::paintGraphicsLayerContents(GraphicsContext& context, const IntRect& clip)
+void GraphicsLayer::paintIfNeeded(GraphicsContext& context)
+{
+    ASSERT(RuntimeEnabledFeatures::slimmingPaintSynchronizedPaintingEnabled());
+    if (!m_client)
+        return;
+    if (firstPaintInvalidationTrackingEnabled())
+        m_debugInfo.clearAnnotatedInvalidateRects();
+    incrementPaintCount();
+    m_client->paintContentsIfNeeded(this, context, m_paintingPhase);
+}
+
+void GraphicsLayer::paint(GraphicsContext& context, const IntRect& clip)
 {
     if (!m_client)
         return;
     if (firstPaintInvalidationTrackingEnabled())
         m_debugInfo.clearAnnotatedInvalidateRects();
     incrementPaintCount();
 #ifndef NDEBUG
     if (m_displayItemList && contentsOpaque() && s_drawDebugRedFill) {
         FloatRect rect(FloatPoint(), size());
         if (!DrawingRecorder::useCachedDrawingIfPossible(context, *this, DisplayItem::DebugRedFill)) {
@@ skipping 852 matching lines @@
     m_scrollableArea = scrollableArea;
 
     // Viewport scrolling may involve pinch zoom and gets routed through
     // WebViewImpl explicitly rather than via GraphicsLayer::didScroll.
     if (isViewport)
         m_layer->layer()->setScrollClient(0);
     else
         m_layer->layer()->setScrollClient(this);
 }
 
-void GraphicsLayer::paint(GraphicsContext& context, const IntRect& clip)
-{
-    paintGraphicsLayerContents(context, clip);
-}
-
-
 void GraphicsLayer::notifyAnimationStarted(double monotonicTime, int group)
 {
     if (m_client)
         m_client->notifyAnimationStarted(this, monotonicTime, group);
 }
 
 void GraphicsLayer::notifyAnimationFinished(double, int group)
 {
     if (m_scrollableArea)
         m_scrollableArea->notifyCompositorAnimationFinished(group);
@@ skipping 24 matching lines @@
 {
     if (!layer) {
         fprintf(stderr, "Cannot showGraphicsLayerTree for (nil).\n");
         return;
     }
 
     String output = layer->layerTreeAsText(blink::LayerTreeIncludesDebugInfo);
     fprintf(stderr, "%s\n", output.utf8().data());
 }
 #endif