Support offscreen contexts which own their backing surface

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

 /*
  * Copyright (C) 2009 Apple Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  * 1. Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
  * 2. Redistributions in binary form must reproduce the above copyright
  *    notice, this list of conditions and the following disclaimer in the
@@ skipping 1617 matching lines @@
                         DOMArrayBufferView* pixels,
                         GLuint offset);
 
  private:
   WebGLRenderingContextBase(HTMLCanvasElement*,
                             OffscreenCanvas*,
                             RefPtr<WebTaskRunner>,
                             std::unique_ptr<WebGraphicsContext3DProvider>,
                             const CanvasContextCreationAttributes&,
                             unsigned);
+  static bool supportOwnOffscreenSurface(ExecutionContext*);
   static std::unique_ptr<WebGraphicsContext3DProvider>
   createContextProviderInternal(HTMLCanvasElement*,
                                 ScriptState*,
                                 const CanvasContextCreationAttributes&,
                                 unsigned);
   void texImageCanvasByGPU(TexImageFunctionID,
                            HTMLCanvasElement*,
                            GLuint,
                            GLenum,
                            GLenum,
@@ skipping 14 matching lines @@
                   context,
                   context->is3d(),
                   context.is3d());
 
 }  // namespace blink
 
 WTF_ALLOW_MOVE_INIT_AND_COMPARE_WITH_MEM_FUNCTIONS(
     blink::WebGLRenderingContextBase::TextureUnitState);
 
 #endif  // WebGLRenderingContextBase_h