Remove all usage of WebGraphicsContext3D in blink unit tests.

third_party/WebKit/Source/platform/graphics/test/FakeGLES2Interface.h

 // Copyright 2016 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 MockGLES2Interface_h
-#define MockGLES2Interface_h
+#ifndef FakeGLES2Interface_h
+#define FakeGLES2Interface_h
 
 #include "gpu/command_buffer/client/gles2_interface_stub.h"
 
-class MockGLES2Interface : public gpu::gles2::GLES2InterfaceStub {
+class FakeGLES2Interface : public gpu::gles2::GLES2InterfaceStub {
 public:
+    // GLES2Interface implementation.
     GLenum GetGraphicsResetStatusKHR() override
     {
         return m_contextLost ? GL_INVALID_OPERATION : GL_NO_ERROR;
     }
 
+    // Methods for tests.
     void setIsContextLost(bool lost) { m_contextLost = lost; }
 
 private:
     bool m_contextLost = false;
 };
 
-#endif // MockGLES2Interface_h
+#endif // FakeGLES2Interface_h