Redirect Skia/Ganesh GL calls to Mesa during the layout tests.

app/gfx/gl/gl_bindings_skia.h

+// Copyright (c) 2011 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 APP_GFX_GL_GL_BINDINGS_SKIA_H_
+#define APP_GFX_GL_GL_BINDINGS_SKIA_H_
+#pragma once
+
+namespace gfx {
+
+// The GPU back-end for skia normally makes direct calls to GLES2\gl.  Call
+// this routine to bind the skia GL implementation to that exported by the
+// app/gfx/gl entry points.
+// Note:  This override is required to allow the skia gl calls to be correctly
+// routed around the command buffers during execution of the DumpRenderTree
+// layout tests.
+void BindSkiaToHostGL();
+
+}
+
+#endif  // APP_GFX_GL_GL_BINDINGS_SKIA_H_