Transmit a X-Chrome-UMA-Enabled bit to Google domains from clients that have UMA enabled.

chrome/browser/net/chrome_network_delegate.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_CHROME_NETWORK_DELEGATE_H_
 #define CHROME_BROWSER_NET_CHROME_NETWORK_DELEGATE_H_
 #pragma once
 
 #include "base/basictypes.h"
 #include "base/compiler_specific.h"
@@ skipping 21 matching lines @@
   // |enable_referrers| should be initialized on the UI thread (see below)
   // beforehand. This object's owner is responsible for cleaning it up at
   // shutdown. If |cookie_settings| is NULL, all cookies are enabled,
   // otherwise, the settings are enforced on all observed network requests.
   ChromeNetworkDelegate(
       ExtensionEventRouterForwarder* event_router,
       ExtensionInfoMap* extension_info_map,
       const policy::URLBlacklistManager* url_blacklist_manager,
       void* profile,
       CookieSettings* cookie_settings,
+      bool is_incognito,
       BooleanPrefMember* enable_referrers);
   virtual ~ChromeNetworkDelegate();
 
   // Binds |enable_referrers| to |pref_service| and moves it to the IO thread.
   // This method should be called on the UI thread.
   static void InitializeReferrersEnabled(BooleanPrefMember* enable_referrers,
                                          PrefService* pref_service);
 
  private:
   // NetworkDelegate implementation.
@@ skipping 24 matching lines @@
       net::URLRequest* request,
       const net::AuthChallengeInfo& auth_info,
       const AuthCallback& callback,
       net::AuthCredentials* credentials) OVERRIDE;
   virtual bool CanGetCookies(const net::URLRequest* request,
                              const net::CookieList& cookie_list) OVERRIDE;
   virtual bool CanSetCookie(const net::URLRequest* request,
                             const std::string& cookie_line,
                             net::CookieOptions* options) OVERRIDE;
 
+  // Adds Chrome experiment and metrics state as custom headers to |headers|
+  // based on local state and |request|.
+  void AddChromeMetricsStateHeader(net::URLRequest* request,
+                                   net::HttpRequestHeaders* headers);
+
   scoped_refptr<ExtensionEventRouterForwarder> event_router_;
   void* profile_;
   scoped_refptr<CookieSettings> cookie_settings_;
 
+  // Whether or not the profile is an Off The Record profile. Note that this

[Ilya Sherman, 2012/04/17 20:55:39]

nit: s/Off The Record/Incognito

+  // field is not valid if |profile_| is NULL, so always check profile_ first
+  // before this field.
+  bool is_incognito_;
+
   scoped_refptr<ExtensionInfoMap> extension_info_map_;
 
   // Weak, owned by our owner.
   BooleanPrefMember* enable_referrers_;
 
   // Weak, owned by our owner.
   const policy::URLBlacklistManager* url_blacklist_manager_;
 
   DISALLOW_COPY_AND_ASSIGN(ChromeNetworkDelegate);
 };
 
 #endif  // CHROME_BROWSER_NET_CHROME_NETWORK_DELEGATE_H_