Adds DevTools commands for forced viewport override.

third_party/WebKit/Source/platform/graphics/GraphicsLayer.cpp

Index: third_party/WebKit/Source/platform/graphics/GraphicsLayer.cpp
diff --git a/third_party/WebKit/Source/platform/graphics/GraphicsLayer.cpp b/third_party/WebKit/Source/platform/graphics/GraphicsLayer.cpp
index 59fafd85c84d2605bf8fb46e9c8d340ab60558cf..b020bbc30ef2afe552f1e7ae33e999892295b32b 100644
--- a/third_party/WebKit/Source/platform/graphics/GraphicsLayer.cpp
+++ b/third_party/WebKit/Source/platform/graphics/GraphicsLayer.cpp
@@ -950,6 +950,11 @@ void GraphicsLayer::setRenderingContext(int context)
         m_contentsLayer->setRenderingContext(m_renderingContext3d);
 }
 
+bool GraphicsLayer::masksToBounds() const
+{
+    return m_layer->layer()->masksToBounds();
+}
+
 void GraphicsLayer::setMasksToBounds(bool masksToBounds)
 {
     m_layer->layer()->setMasksToBounds(masksToBounds);