WebGL: add targets for WebGL 2 when check FBO targets

Source/core/html/canvas/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 "core/html/canvas/WebGLExtension.h"
 #include "core/html/canvas/WebGLRenderingContextBase.h"
 #include "wtf/PassRefPtr.h"
@@ skipping 159 matching lines @@
     WebGL2RenderingContextBase(HTMLCanvasElement*, PassOwnPtr<blink::WebGraphicsContext3D>, const WebGLContextAttributes& requestedAttributes);
 
     bool validateClearBuffer(const char* functionName, GLenum buffer, GLsizei length);
 
     ScriptValue getInt64Parameter(ScriptState*, GLenum);
 
     /* WebGLRenderingContextBase overrides */
     bool validateCapability(const char* functionName, GLenum) override;
     bool validateBufferTarget(const char* functionName, GLenum target) override;
     bool validateAndUpdateBufferBindTarget(const char* functionName, GLenum, WebGLBuffer*) override;
+    bool validateFramebufferTarget(GLenum target) override;
 
     RefPtrWillBeMember<WebGLFramebuffer> m_readFramebufferBinding;
 };
 
 DEFINE_TYPE_CASTS(WebGL2RenderingContextBase, CanvasRenderingContext, context,
     context->is3d() && WebGLRenderingContextBase::getWebGLVersion(context) >= 2,
     context.is3d() && WebGLRenderingContextBase::getWebGLVersion(&context) >= 2);
 
 } // namespace blink
 
 #endif