Merge 114791 - [chromium] Clip TransparencyWin to prevent OOM from large Skia canvas

Source/WebCore/platform/graphics/chromium/TransparencyWin.cpp

 /*
  * Copyright (C) 2009 Google 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:
  * 
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
  *     * Redistributions in binary form must reproduce the above
@@ skipping 192 matching lines @@
 void TransparencyWin::computeLayerSize()
 {
     if (m_transformMode == Untransform) {
         // The meaning of the "transformed" source rect is a little ambigous
         // here. The rest of the code doesn't care about it in the Untransform
         // case since we're using our own happy coordinate system. So we set it
         // to be the source rect since that matches how the code below actually
         // uses the variable: to determine how to translate things to account
         // for the offset of the layer.
         m_transformedSourceRect = m_sourceRect;
-        m_layerSize = IntSize(m_sourceRect.width(), m_sourceRect.height());
-    } else {
+    } else if (m_transformMode == KeepTransform && m_layerMode != TextComposite) {
+        // FIXME: support clipping for other modes
+        IntRect clippedSourceRect = m_sourceRect;
+        SkRect clipBounds;
+        if (m_destContext->platformContext()->canvas()->getClipBounds(&clipBounds)) {
+            FloatRect clipRect(clipBounds.left(), clipBounds.top(), clipBounds.width(), clipBounds.height());
+            clippedSourceRect.intersect(enclosingIntRect(clipRect));
+        }
+        m_transformedSourceRect = m_orgTransform.mapRect(clippedSourceRect);
+    } else
         m_transformedSourceRect = m_orgTransform.mapRect(m_sourceRect);
-        m_layerSize = IntSize(m_transformedSourceRect.width(), m_transformedSourceRect.height());
-    }
+
+    m_layerSize = IntSize(m_transformedSourceRect.width(), m_transformedSourceRect.height());
 }
 
 void TransparencyWin::setupLayer()
 {
     switch (m_layerMode) {
     case NoLayer:
         setupLayerForNoLayer();
         break;
     case OpaqueCompositeLayer:
         setupLayerForOpaqueCompositeLayer();
@@ skipping 276 matching lines @@
     SkBitmap& bitmap = const_cast<SkBitmap&>(m_drawContext->platformContext()->
         canvas()->getTopDevice()->accessBitmap(true));
     for (int y = 0; y < m_layerSize.height(); y++) {
         uint32_t* row = bitmap.getAddr32(0, y);
         for (int x = 0; x < m_layerSize.width(); x++)
             row[x] |= 0xFF000000;
     }
 }
 
 } // namespace WebCore