Pass accurate contentsScale to LayerImpl.

cc/render_surface_impl.cc

 // Copyright 2011 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "config.h"
 
 #include "cc/render_surface_impl.h"
 
 #include "base/logging.h"
 #include "base/stringprintf.h"
@@ skipping 218 matching lines @@
         maskLayer = m_owningLayer->replicaLayer()->maskLayer();
         if (maskLayer && (!maskLayer->drawsContent() || maskLayer->bounds().isEmpty()))
             maskLayer = 0;
     }
 
     float maskTexCoordScaleX = 1;
     float maskTexCoordScaleY = 1;
     float maskTexCoordOffsetX = 0;
     float maskTexCoordOffsetY = 0;
     if (maskLayer) {
-        maskTexCoordScaleX = static_cast<float>(contentRect().width()) / maskLayer->contentBounds().width();
-        maskTexCoordScaleY = static_cast<float>(contentRect().height()) / maskLayer->contentBounds().height();
+        maskTexCoordScaleX = contentRect().width() / maskLayer->contentsScaleX() / maskLayer->bounds().width();
+        maskTexCoordScaleY = contentRect().height() / maskLayer->contentsScaleY() / maskLayer->bounds().height();
         maskTexCoordOffsetX = static_cast<float>(contentRect().x()) / contentRect().width() * maskTexCoordScaleX;
         maskTexCoordOffsetY = static_cast<float>(contentRect().y()) / contentRect().height() * maskTexCoordScaleY;
     }
 
     ResourceProvider::ResourceId maskResourceId = maskLayer ? maskLayer->contentsResourceId() : 0;
     IntRect contentsChangedSinceLastFrame = contentsChanged() ? m_contentRect : IntRect();
 
     quadSink.append(RenderPassDrawQuad::create(sharedQuadState, contentRect(), renderPassId, forReplica, maskResourceId, contentsChangedSinceLastFrame,
                                                  maskTexCoordScaleX, maskTexCoordScaleY, maskTexCoordOffsetX, maskTexCoordOffsetY).PassAs<DrawQuad>(), appendQuadsData);
 }
 
 }