Removed partial Client Hints implementation from the Chrome side.

chrome/browser/net/client_hints.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_BROWSER_NET_CLIENT_HINTS_H_
-#define CHROME_BROWSER_NET_CLIENT_HINTS_H_
-
-#include <string>
-
-#include "base/basictypes.h"
-#include "base/memory/weak_ptr.h"
-
-// ClientHints is a repository in Chrome for information used
-// to create the Client-Hints request header. For more information, see:
-// https://github.com/igrigorik/http-client-hints/blob/draft2/draft-grigorik-http-client-hints-01.txt
-class ClientHints {
- public:
-  static const char kDevicePixelRatioHeader[];
-
-  ClientHints();
-  ~ClientHints();
-
-  void Init();
-
-  // Returns the device pixel ratio as a string.  Its value is the same as
-  // window.devicePixelRatio in Javascript.
-  const std::string& GetDevicePixelRatioHeader() const;
-
- private:
-  friend class ClientHintsTest;
-
-  // Retrieves and updates screen information for use on the IO thread.
-  bool RetrieveScreenInfo();
-
-  void UpdateScreenInfo(float device_pixel_ratio_value);
-
-  std::string screen_hints_;
-
-  base::WeakPtrFactory<ClientHints> weak_ptr_factory_;
-
-  DISALLOW_COPY_AND_ASSIGN(ClientHints);
-};
-
-#endif  // CHROME_BROWSER_NET_CLIENT_HINTS_H_