Expose GLES2Interface to blink, and delete isContextLost() from WGC3D.

third_party/WebKit/Source/platform/graphics/test/MockGLES2Interface.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
+
+#include "gpu/command_buffer/client/gles2_interface_stub.h"
+
+class MockGLES2Interface : public gpu::gles2::GLES2InterfaceStub {
+public:
+    GLenum GetGraphicsResetStatusKHR() override
+    {
+        return m_contextLost ? GL_INVALID_OPERATION : GL_NO_ERROR;
+    }
+
+    void setIsContextLost(bool lost) { m_contextLost = lost; }
+
+private:
+    bool m_contextLost = false;
+};
+
+#endif // MockGLES2Interface_h