Changes subtreeShouldRenderToSeparateSurface logic to account for explicit clipping

cc/layer_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 "cc/layer_impl.h"
 
 #include "base/debug/trace_event.h"
 #include "base/stringprintf.h"
 #include "base/values.h"
 #include "cc/animation_registrar.h"
@@ skipping 269 matching lines @@
 
 gfx::Rect LayerImpl::layerRectToContentRect(const gfx::RectF& layerRect) const
 {
     gfx::RectF contentRect = gfx::ScaleRect(layerRect, contentsScaleX(), contentsScaleY());
     // Intersect with content rect to avoid the extra pixel because for some
     // values x and y, ceil((x / y) * y) may be x + 1.
     contentRect.Intersect(gfx::Rect(gfx::Point(), contentBounds()));
     return gfx::ToEnclosingRect(contentRect);
 }
 
+bool LayerImpl::canClipSelf() const
+{
+    return false;
+}
+
 std::string LayerImpl::indentString(int indent)
 {
     std::string str;
     for (int i = 0; i != indent; ++i)
         str.append("  ");
     return str;
 }
 
 void LayerImpl::dumpLayerProperties(std::string* str, int indent) const
 {
@@ skipping 547 matching lines @@
         if (m_layerTreeImpl->settings().useLinearFadeScrollbarAnimator)
             m_scrollbarAnimationController = createScrollbarAnimationControllerWithFade(this);
         else
             m_scrollbarAnimationController = ScrollbarAnimationController::create(this);
     }
     m_scrollbarAnimationController->setVerticalScrollbarLayer(scrollbarLayer);
     m_scrollbarAnimationController->updateScrollOffset(this);
 }
 
 }  // namespace cc