Preparation for enabling slimming paint synchronized painting

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 281 matching lines @@
 }
 
 void GraphicsLayer::paintIfNeeded(GraphicsContext& context)
 {
     ASSERT(RuntimeEnabledFeatures::slimmingPaintSynchronizedPaintingEnabled());
     if (!m_client)
         return;
     if (firstPaintInvalidationTrackingEnabled())
         m_debugInfo.clearAnnotatedInvalidateRects();
     incrementPaintCount();
+#ifndef NDEBUG
+    if (m_paintController && contentsOpaque() && s_drawDebugRedFill) {
+        FloatRect rect(FloatPoint(), size());
+        if (!DrawingRecorder::useCachedDrawingIfPossible(context, *this, DisplayItem::DebugRedFill)) {
+            DrawingRecorder recorder(context, *this, DisplayItem::DebugRedFill, rect);
+            context.fillRect(rect, SK_ColorRED);
+        }
+    }
+#endif

[Xianzhu, 2015/10/28 18:10:23]

These are copied from GraphicsLayer::paint().

Perhaps we can combine paintIfNeeded() and paint(). I have another CL for this
(WIP): https://codereview.chromium.org/1428643004.

     m_client->paintContentsIfNeeded(this, context, m_paintingPhase);
+    if (!m_textPainted && m_paintController->textPainted()) {
+        m_textPainted = true;
+        m_client->notifyTextPainted();
+    }
 }
 
 void GraphicsLayer::paint(GraphicsContext& context, const IntRect& clip)
 {
     if (!m_client)
         return;
     if (firstPaintInvalidationTrackingEnabled())
         m_debugInfo.clearAnnotatedInvalidateRects();
     incrementPaintCount();
 #ifndef NDEBUG
@@ skipping 869 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