[Oilpan] Prepare full definition of classes before using Member

third_party/WebKit/Source/core/html/HTMLCanvasElement.cpp

Index: third_party/WebKit/Source/core/html/HTMLCanvasElement.cpp
diff --git a/third_party/WebKit/Source/core/html/HTMLCanvasElement.cpp b/third_party/WebKit/Source/core/html/HTMLCanvasElement.cpp
index bf12c2feaf31ba82571f7577f0a1568762032aff..c9624691f6857f3c90b45443a89c8f1e06a925cd 100644
--- a/third_party/WebKit/Source/core/html/HTMLCanvasElement.cpp
+++ b/third_party/WebKit/Source/core/html/HTMLCanvasElement.cpp
@@ -786,6 +786,11 @@ SkCanvas* HTMLCanvasElement::existingDrawingCanvas() const
     return m_imageBuffer->canvas();
 }
 
+CanvasRenderingContext* HTMLCanvasElement::renderingContext() const
+{
+    return m_context.get();
+}
+
 ImageBuffer* HTMLCanvasElement::buffer() const
 {
     ASSERT(m_context);