[Oilpan] Prepare full definition of classes before using Member

third_party/WebKit/Source/modules/webgl/WebGLRenderingContextBase.cpp

Index: third_party/WebKit/Source/modules/webgl/WebGLRenderingContextBase.cpp
diff --git a/third_party/WebKit/Source/modules/webgl/WebGLRenderingContextBase.cpp b/third_party/WebKit/Source/modules/webgl/WebGLRenderingContextBase.cpp
index 2fc71ec96469d625e50418ccf0b4bc094c3f575c..f90828cc3597870f9c4ad2332a8962b227e45c44 100644
--- a/third_party/WebKit/Source/modules/webgl/WebGLRenderingContextBase.cpp
+++ b/third_party/WebKit/Source/modules/webgl/WebGLRenderingContextBase.cpp
@@ -121,6 +121,22 @@ WebGLRenderingContextBaseMap& forciblyEvictedContexts()
 
 } // namespace
 
+WebGLRenderingContextBase::ScopedDrawingBufferBinder::ScopedDrawingBufferBinder(DrawingBuffer* drawingBuffer, WebGLFramebuffer* framebufferBinding)
+    : m_drawingBuffer(drawingBuffer)
+    , m_readFramebufferBinding(framebufferBinding)
+{
+    // Commit DrawingBuffer if needed (e.g., for multisampling)
+    if (!m_readFramebufferBinding && m_drawingBuffer)
+        m_drawingBuffer->commit();
+}
+
+WebGLRenderingContextBase::ScopedDrawingBufferBinder::~ScopedDrawingBufferBinder()
+{
+    // Restore DrawingBuffer if needed
+    if (!m_readFramebufferBinding && m_drawingBuffer)
+        m_drawingBuffer->restoreFramebufferBindings();
+}
+
 void WebGLRenderingContextBase::forciblyLoseOldestContext(const String& reason)
 {
     WebGLRenderingContextBase* candidate = oldestContext();