Add Spdy4Experiment group.

chrome/browser/io_thread.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_IO_THREAD_H_
 #define CHROME_BROWSER_IO_THREAD_H_
 
 #include <string>
 #include <vector>
 
 #include "base/basictypes.h"
 #include "base/compiler_specific.h"
 #include "base/memory/ref_counted.h"
 #include "base/memory/scoped_ptr.h"
 #include "base/memory/weak_ptr.h"
 #include "base/prefs/pref_member.h"
+#include "base/strings/string_piece.h"
 #include "base/time/time.h"
 #include "chrome/browser/net/chrome_network_delegate.h"
 #include "chrome/browser/net/ssl_config_service_manager.h"
 #include "content/public/browser/browser_thread.h"
 #include "content/public/browser/browser_thread_delegate.h"
 #include "net/base/network_change_notifier.h"
 #include "net/http/http_network_session.h"
 #include "net/socket/next_proto.h"
 
 class ChromeNetLog;
@@ skipping 255 matching lines @@
   //   "force-alt-protocols       : Forces an alternate protocol of SPDY/3
   //                                on port 443.
   //   "single-domain"            : Forces all spdy traffic to a single domain.
   //   "init-max-streams=<limit>" : Specifies the maximum number of concurrent
   //                                streams for a SPDY session, unless the
   //                                specifies a different value via SETTINGS.
   void EnableSpdy(const std::string& mode);
 
   // Configures available SPDY protocol versions from the given trial.
   // Used only if no command-line configuration was present.
-  static void ConfigureSpdyFromTrial(const std::string& spdy_trial_group,
+  static void ConfigureSpdyFromTrial(base::StringPiece spdy_trial_group,
                                      Globals* globals);
 
   // Global state must be initialized on the IO thread, then this
   // method must be invoked on the UI thread.
   void InitSystemRequestContext();
 
   // Lazy initialization of system request context for
   // SystemURLRequestContextGetter. To be called on IO thread only
   // after global state has been initialized on the IO thread, and
   // SystemRequestContext state has been initialized on the UI thread.
@@ skipping 156 matching lines @@
   bool is_spdy_disabled_by_policy_;
 
   const base::TimeTicks creation_time_;
 
   base::WeakPtrFactory<IOThread> weak_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(IOThread);
 };
 
 #endif  // CHROME_BROWSER_IO_THREAD_H_