Move extensions bindings code out of //chrome

chrome/renderer/extensions/css_native_handler.h

-// Copyright 2013 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 CHROME_RENDERER_EXTENSIONS_CSS_NATIVE_HANDLER_H_
-#define CHROME_RENDERER_EXTENSIONS_CSS_NATIVE_HANDLER_H_
-
-#include "extensions/renderer/object_backed_native_handler.h"
-
-namespace extensions {
-class ChromeV8Context;
-
-class CssNativeHandler : public ObjectBackedNativeHandler {
- public:
-  explicit CssNativeHandler(ChromeV8Context* context);
-
- private:
-  // Expects one string argument that's a comma-separated list of compound CSS
-  // selectors (http://dev.w3.org/csswg/selectors4/#compound), and returns its
-  // Blink-canonicalized form. If the selector is invalid, returns an empty
-  // string.
-  void CanonicalizeCompoundSelector(
-      const v8::FunctionCallbackInfo<v8::Value>& args);
-};
-
-}  // namespace extensions
-
-#endif  // CHROME_RENDERER_EXTENSIONS_CSS_NATIVE_HANDLER_H_