Added Client-Hints.

chrome/browser/net/client_hints.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 CHROME_BROWSER_NET_CLIENT_HINTS_H_
+#define CHROME_BROWSER_NET_CLIENT_HINTS_H_
+
+#include <string>
+
+#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/master/
+// draft-grigorik-http-client-hints-00.txt
+class ClientHints : public base::RefCountedThreadSafe<ClientHints> {

[Ryan Sleevi, 2013/02/26 02:21:04]

This is still RefCounted, but you said you were going WeakPtr.

The goal is to eliminate RefCounting from being part of the public interface
(and ideally, keep it from being introduced in the private / implementation
details part)

[bengr, 2013/02/26 18:19:53]

Oops. I meant to get rid of this. Done.

On 2013/02/26 02:21:04, Ryan Sleevi wrote:

+ public:
+  ClientHints();
+
+  // Retrieves screen information for use on the IO thread.
+  bool RetrieveScreenInfo();
+
+  // Returns client hints pertaining to screen information. The format is:
+  // "dh=x, dw=y, dpr=z", where x, y, and z are the device screen height,
+  // screen width, and pixel ratio, respectively. These values are the
+  // same as the values returned by the JavaScript commands:
+  // screen.height, screen.width, and window.devicePixelRatio.
+  std::string GetScreenInfoHints();
+
+  // Contains information about the client device.
+  struct ScreenInfo {
+    int width;
+    int height;
+    float pixel_ratio;
+  };

[Ryan Sleevi, 2013/02/26 02:21:04]

Usually we place these declarations first (part of the public) -
http://google-styleguide.googlecode.com/svn/trunk/cppguide.xml?showone=Declar...

[bengr, 2013/02/26 18:19:53]

Done.

+
+ private:
+  friend class ClientHintsTest;
+  friend class base::RefCountedThreadSafe<ClientHints>;
+
+  ~ClientHints();
+  void UpdateScreenInfo(ScreenInfo* info);
+
+  std::string screen_hints_;
+
+  base::WeakPtrFactory<ClientHints> weak_ptr_factory_;
+
+  DISALLOW_COPY_AND_ASSIGN(ClientHints);
+};
+
+#endif  // CHROME_BROWSER_NET_CLIENT_HINTS_H_