Correct the OffscreenCanvas.getContext API

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

 // Copyright 2015 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef WebGL2RenderingContextBase_h
 #define WebGL2RenderingContextBase_h
 
 #include "bindings/core/v8/ScriptPromise.h"
 #include "bindings/core/v8/TraceWrapperMember.h"
 #include "modules/webgl/WebGLExtension.h"
@@ skipping 737 matching lines @@
   DECLARE_VIRTUAL_TRACE();
   DECLARE_VIRTUAL_TRACE_WRAPPERS();
 
  protected:
   friend class V8WebGL2RenderingContext;
 
   WebGL2RenderingContextBase(
       HTMLCanvasElement*,
       std::unique_ptr<WebGraphicsContext3DProvider>,
       const CanvasContextCreationAttributes& requestedAttributes);
+  WebGL2RenderingContextBase(
+      OffscreenCanvas*,
+      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.
   bool validateGetFramebufferAttachmentParameterFunc(const char* functionName,
                                                      GLenum target,
                                                      GLenum attachment);
@@ skipping 152 matching lines @@
                   context,
                   context->is3d() &&
                       WebGLRenderingContextBase::getWebGLVersion(context) >= 2,
                   context.is3d() &&
                       WebGLRenderingContextBase::getWebGLVersion(&context) >=
                           2);
 
 }  // namespace blink
 
 #endif