Make WebGLRenderingContext.getSupportedExtensions() return type nullable

Source/core/html/canvas/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
  *    documentation and/or other materials provided with the distribution.
  *
  * THIS SOFTWARE IS PROVIDED BY APPLE COMPUTER, INC. ``AS IS'' AND ANY
  * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL APPLE COMPUTER, INC. OR
  * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
  * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
  * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
  * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
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 #ifndef WebGLRenderingContextBase_h
 #define WebGLRenderingContextBase_h
 
+#include "bindings/core/v8/Nullable.h"
 #include "core/dom/ActiveDOMObject.h"
 #include "core/html/canvas/CanvasRenderingContext.h"
 #include "core/html/canvas/WebGLExtensionName.h"
 #include "core/html/canvas/WebGLGetInfo.h"
 #include "core/page/Page.h"
 #include "core/rendering/RenderBoxModelObject.h"
 #include "platform/Timer.h"
 #include "platform/graphics/GraphicsTypes3D.h"
 #include "platform/graphics/ImageBuffer.h"
 #include "platform/graphics/gpu/DrawingBuffer.h"
@@ skipping 154 matching lines @@
     PassRefPtr<WebGLExtension> getExtension(const String& name);
     WebGLGetInfo getFramebufferAttachmentParameter(GLenum target, GLenum attachment, GLenum pname);
     WebGLGetInfo getParameter(GLenum pname);
     WebGLGetInfo getProgramParameter(WebGLProgram*, GLenum pname);
     String getProgramInfoLog(WebGLProgram*);
     WebGLGetInfo getRenderbufferParameter(GLenum target, GLenum pname);
     WebGLGetInfo getShaderParameter(WebGLShader*, GLenum pname);
     String getShaderInfoLog(WebGLShader*);
     PassRefPtr<WebGLShaderPrecisionFormat> getShaderPrecisionFormat(GLenum shaderType, GLenum precisionType);
     String getShaderSource(WebGLShader*);
-    Vector<String> getSupportedExtensions();
+    Nullable<Vector<String> > getSupportedExtensions();
     WebGLGetInfo getTexParameter(GLenum target, GLenum pname);
     WebGLGetInfo getUniform(WebGLProgram*, const WebGLUniformLocation*);
     PassRefPtr<WebGLUniformLocation> getUniformLocation(WebGLProgram*, const String&);
     WebGLGetInfo getVertexAttrib(GLuint index, GLenum pname);
     long long getVertexAttribOffset(GLuint index, GLenum pname);
 
     void hint(GLenum target, GLenum mode);
     GLboolean isBuffer(WebGLBuffer*);
     bool isContextLost() const;
     GLboolean isEnabled(GLenum cap);
@@ skipping 688 matching lines @@
     // If the vector is empty, return the maximum allowed active context number.
     static size_t oldestContextIndex();
     static IntSize oldestContextSize();
 };
 
 DEFINE_TYPE_CASTS(WebGLRenderingContextBase, CanvasRenderingContext, context, context->is3d(), context.is3d());
 
 } // namespace WebCore
 
 #endif // WebGLRenderingContextBase_h