[content shell] move code common to several processes to a common dir

content/shell/shell_content_client.h

-// Copyright (c) 2012 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 CONTENT_SHELL_SHELL_CONTENT_CLIENT_H_
-#define CONTENT_SHELL_SHELL_CONTENT_CLIENT_H_
-
-#include <string>
-#include <vector>
-
-#include "base/compiler_specific.h"
-#include "content/public/common/content_client.h"
-
-namespace content {
-
-class ShellContentClient : public ContentClient {
- public:
-  virtual ~ShellContentClient();
-
-  virtual std::string GetUserAgent() const OVERRIDE;
-  virtual string16 GetLocalizedString(int message_id) const OVERRIDE;
-  virtual base::StringPiece GetDataResource(
-      int resource_id,
-      ui::ScaleFactor scale_factor) const OVERRIDE;
-  virtual base::RefCountedStaticMemory* GetDataResourceBytes(
-      int resource_id) const OVERRIDE;
-  virtual gfx::Image& GetNativeImageNamed(int resource_id) const OVERRIDE;
-};
-
-}  // namespace content
-
-#endif  // CONTENT_SHELL_SHELL_CONTENT_CLIENT_H_