Refactor RenderThemeChromiumDefault

Source/core/rendering/RenderThemeChromiumLinux.h

Index: Source/core/rendering/RenderThemeChromiumLinux.h
diff --git a/Source/core/rendering/RenderThemeChromiumLinux.h b/Source/core/rendering/RenderThemeChromiumLinux.h
new file mode 100644
index 0000000000000000000000000000000000000000..47736a69d24680e2b394a0a8d4683af47ee1f44a
--- /dev/null
+++ b/Source/core/rendering/RenderThemeChromiumLinux.h
@@ -0,0 +1,20 @@
+// Copyright 2014 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 RenderThemeChromiumLinux_h
+#define RenderThemeChromiumLinux_h
+
+#include "core/rendering/RenderThemeChromiumDefault.h"
+
+namespace blink {
+
+class RenderThemeChromiumLinux final : public RenderThemeChromiumDefault {
+public:
+    static PassRefPtr<RenderTheme> create();
+    virtual String extraDefaultStyleSheet() override;
+};
+
+} // namespace blink
+
+#endif // RenderThemeChromiumLinux_h