Fix crash from state management cleanup

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

Index: third_party/WebKit/Source/modules/webgl/WebGLRenderingContextBase.h
diff --git a/third_party/WebKit/Source/modules/webgl/WebGLRenderingContextBase.h b/third_party/WebKit/Source/modules/webgl/WebGLRenderingContextBase.h
index 73bbe090b2905cdcdd281d491ed3868cd1b65a02..ce173d6047db2043831716021f2c0bc1048be620 100644
--- a/third_party/WebKit/Source/modules/webgl/WebGLRenderingContextBase.h
+++ b/third_party/WebKit/Source/modules/webgl/WebGLRenderingContextBase.h
@@ -132,7 +132,8 @@ class ScopedRGBEmulationColorMask {
   const bool m_requiresEmulation;
 };
 
-class MODULES_EXPORT WebGLRenderingContextBase : public CanvasRenderingContext {
+class MODULES_EXPORT WebGLRenderingContextBase : public CanvasRenderingContext,
+                                                 public DrawingBuffer::Client {
   WTF_MAKE_NONCOPYABLE(WebGLRenderingContextBase);
 
  public:
@@ -545,11 +546,7 @@ class MODULES_EXPORT WebGLRenderingContextBase : public CanvasRenderingContext {
   void restoreScissorEnabled();
   void restoreScissorBox();
   void restoreClearColor();
-  void restoreClearDepthf();
-  void restoreClearStencil();
-  void restoreStencilMaskSeparate();
   void restoreColorMask();
-  void restoreDepthMask();
 
   gpu::gles2::GLES2Interface* contextGL() const {
     DrawingBuffer* d = drawingBuffer();
@@ -619,6 +616,7 @@ class MODULES_EXPORT WebGLRenderingContextBase : public CanvasRenderingContext {
   friend class WebGLCompressedTextureS3TCsRGB;
   friend class WebGLRenderingContextErrorMessageCallback;
   friend class WebGLVertexArrayObjectBase;
+  friend class ScopedDrawingBufferBinder;
   friend class ScopedTexture2DRestorer;
   friend class ScopedFramebufferRestorer;
   // To allow V8WebGL[2]RenderingContext to call visitChildDOMWrappers.
@@ -645,6 +643,16 @@ class MODULES_EXPORT WebGLRenderingContextBase : public CanvasRenderingContext {
   WebLayer* platformLayer() const override;
   void stop() override;
 
+  // DrawingBuffer::Client implementation.
+  bool DrawingBufferClientIsBoundForDraw() override;
+  void DrawingBufferClientRestoreScissorTest() override;
+  void DrawingBufferClientRestoreMaskAndClearValues() override;
+  void DrawingBufferClientRestorePixelPackAlignment() override;
+  void DrawingBufferClientRestoreTexture2DBinding() override;
+  void DrawingBufferClientRestoreRenderbufferBinding() override;
+  void DrawingBufferClientRestoreFramebufferBinding() override;
+  void DrawingBufferClientRestorePixelUnpackBufferBinding() override;
+
   void addSharedObject(WebGLSharedObject*);
   void addContextObject(WebGLContextObject*);
   void detachAndRemoveAllObjects();
@@ -915,7 +923,7 @@ class MODULES_EXPORT WebGLRenderingContextBase : public CanvasRenderingContext {
           m_readFramebufferBinding(framebufferBinding) {
       // Commit DrawingBuffer if needed (e.g., for multisampling)
       if (!m_readFramebufferBinding && m_drawingBuffer)
-        m_drawingBuffer->commit();
+        m_drawingBuffer->resolveAndBindForReadAndDraw();
     }
 
     ~ScopedDrawingBufferBinder() {
@@ -975,9 +983,6 @@ class MODULES_EXPORT WebGLRenderingContextBase : public CanvasRenderingContext {
   };
   HowToClear clearIfComposited(GLbitfield clearMask = 0);
 
-  // Helper to restore state that clearing the framebuffer may destroy.
-  void restoreStateAfterClear();
-
   // Convert texture internal format.
   GLenum convertTexInternalFormat(GLenum internalformat, GLenum type);