Fix crash from state management cleanup

third_party/WebKit/Source/modules/webgl/WebGL2RenderingContextBase.h

Index: third_party/WebKit/Source/modules/webgl/WebGL2RenderingContextBase.h
diff --git a/third_party/WebKit/Source/modules/webgl/WebGL2RenderingContextBase.h b/third_party/WebKit/Source/modules/webgl/WebGL2RenderingContextBase.h
index 23479a91c40c872683f81e18756676d6259718c6..d3e12c874261f40d9a74dd3013e65d81f3457ef1 100644
--- a/third_party/WebKit/Source/modules/webgl/WebGL2RenderingContextBase.h
+++ b/third_party/WebKit/Source/modules/webgl/WebGL2RenderingContextBase.h
@@ -728,6 +728,9 @@ class WebGL2RenderingContextBase : public WebGLRenderingContextBase {
       std::unique_ptr<WebGraphicsContext3DProvider>,
       const CanvasContextCreationAttributes& requestedAttributes);
 
+  // DrawingBuffer::Client implementation.
+  void DrawingBufferClientRestorePixelUnpackBufferBinding() override;
+
   // Helper function to validate target and the attachment combination for
   // getFramebufferAttachmentParameters.  Generate GL error and return false if
   // parameters are illegal.