Collect UMA statistics on which chrome://flags lead to chrome restart on ChromeOS.

chrome/browser/about_flags.h

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.

[Nikita (slow), 2014/06/19 17:08:07]

How about adding comment somewhere in this file (not sure that it will get
noticed though but still) to add new flags to array?

[Alexander Alekseev, 2014/06/19 18:17:47]

Done.

 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef CHROME_BROWSER_ABOUT_FLAGS_H_
 #define CHROME_BROWSER_ABOUT_FLAGS_H_
 
 #include <map>
+#include <set>
 #include <string>
 
 #include "base/command_line.h"
 #include "base/strings/string16.h"
 
 class PrefService;
 
 namespace base {
 class ListValue;
 }
@@ skipping 91 matching lines @@
 enum SentinelsMode { kNoSentinels, kAddSentinels };
 
 // Reads the Labs |prefs| (called "Labs" for historical reasons) and adds the
 // commandline flags belonging to the active experiments to |command_line|.
 void ConvertFlagsToSwitches(FlagsStorage* flags_storage,
                             base::CommandLine* command_line,
                             SentinelsMode sentinels);
 
 // Compares a set of switches of the two provided command line objects and
 // returns true if they are the same and false otherwise.
+// If |out_difference| is not NULL, it's filled with set_symmetric_difference
+// between sets.
 bool AreSwitchesIdenticalToCurrentCommandLine(
     const base::CommandLine& new_cmdline,
-    const base::CommandLine& active_cmdline);
+    const base::CommandLine& active_cmdline,
+    std::set<CommandLine::StringType>* out_difference);
 
 // Differentiate between generic flags available on a per session base and flags
 // that influence the whole machine and can be said by the admin only. This flag
 // is relevant for ChromeOS for now only and dictates whether entries marked
 // with the |kOsCrOSOwnerOnly| label should be enabled in the UI or not.
 enum FlagAccess { kGeneralAccessFlagsOnly, kOwnerAccessToFlags };
 
 // Get the list of experiments. Experiments that are available on the current
 // platform are appended to |supported_experiments|; all other experiments are
 // appended to |unsupported_experiments|.
@@ skipping 41 matching lines @@
 
 // Separator used for multi values. Multi values are represented in prefs as
 // name-of-experiment + kMultiSeparator + selected_index.
 extern const char kMultiSeparator[];
 
 }  // namespace testing
 
 }  // namespace about_flags
 
 #endif  // CHROME_BROWSER_ABOUT_FLAGS_H_