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

chrome/browser/chromeos/login/login_utils.cc

 // 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.
 
 #include "chrome/browser/chromeos/login/login_utils.h"
 
 #include <algorithm>
 #include <set>
 #include <vector>
 
@@ skipping 74 matching lines @@
 #include "content/public/browser/browser_thread.h"
 #include "content/public/browser/notification_service.h"
 #include "google_apis/gaia/gaia_auth_consumer.h"
 #include "net/base/network_change_notifier.h"
 #include "net/url_request/url_request_context.h"
 #include "net/url_request/url_request_context_getter.h"
 #include "url/gurl.h"
 
 using content::BrowserThread;
 
+namespace {
+
+void LogCustomSwitches(const std::set<std::string>& switches) {
+  if (!VLOG_IS_ON(1))
+    return;
+  for (std::set<std::string>::const_iterator it = switches.begin();
+       it != switches.end();
+       ++it) {
+    VLOG(1) << "Switch leading to restart: '" << *it << "'";
+  }
+}
+
+}  // anonymous namespace
+
 namespace chromeos {
 
 namespace {
 
 // Returns new CommandLine with per-user flags.
 CommandLine CreatePerSessionCommandLine(Profile* profile) {
   CommandLine user_flags(CommandLine::NO_PROGRAM);
   about_flags::PrefServiceFlagsStorage flags_storage_(profile->GetPrefs());
   about_flags::ConvertFlagsToSwitches(
       &flags_storage_, &user_flags, about_flags::kAddSentinels);
   return user_flags;
 }
 
 // Returns true if restart is needed to apply per-session flags.
-bool NeedRestartToApplyPerSessionFlags(const CommandLine& user_flags) {
+bool NeedRestartToApplyPerSessionFlags(
+    const CommandLine& user_flags,
+    std::set<CommandLine::StringType>* out_command_line_difference) {
   // Don't restart browser if it is not first profile in session.
   if (user_manager::UserManager::Get()->GetLoggedInUsers().size() != 1)
     return false;
 
   // Only restart if needed and if not going into managed mode.
   if (user_manager::UserManager::Get()->IsLoggedInAsSupervisedUser())
     return false;
 
   if (about_flags::AreSwitchesIdenticalToCurrentCommandLine(
-          user_flags, *CommandLine::ForCurrentProcess())) {
+          user_flags,
+          *CommandLine::ForCurrentProcess(),
+          out_command_line_difference)) {
     return false;
   }
 
   return true;
 }
 
 bool CanPerformEarlyRestart() {
   // Desktop build is used for development only. Early restart is not supported.
   if (!base::SysInfo::IsRunningOnChromeOS())
     return false;
@@ skipping 222 matching lines @@
 
 bool LoginUtilsImpl::RestartToApplyPerSessionFlagsIfNeed(Profile* profile,
                                                          bool early_restart) {
   if (ProfileHelper::IsSigninProfile(profile))
     return false;
 
   if (early_restart && !CanPerformEarlyRestart())
     return false;
 
   const CommandLine user_flags(CreatePerSessionCommandLine(profile));
-  if (!NeedRestartToApplyPerSessionFlags(user_flags))
+  std::set<CommandLine::StringType> command_line_difference;
+  if (!NeedRestartToApplyPerSessionFlags(user_flags, &command_line_difference))
     return false;
 
+  LogCustomSwitches(command_line_difference);
+
+  about_flags::ReportCustomFlags("Login.CustomFlags", command_line_difference);
+
   CommandLine::StringVector flags;
   // argv[0] is the program name |CommandLine::NO_PROGRAM|.
   flags.assign(user_flags.argv().begin() + 1, user_flags.argv().end());
   VLOG(1) << "Restarting to apply per-session flags...";
   DBusThreadManager::Get()->GetSessionManagerClient()->SetFlagsForUser(
       user_manager::UserManager::Get()->GetActiveUser()->email(), flags);
   AttemptRestart(profile);
   return true;
 }
 
@@ skipping 88 matching lines @@
   CrosSettings* cros_settings = CrosSettings::Get();
   bool allow_new_user = false;
   cros_settings->GetBoolean(kAccountsPrefAllowNewUser, &allow_new_user);
   if (allow_new_user)
     return true;
   return cros_settings->FindEmailInList(
       kAccountsPrefUsers, username, wildcard_match);
 }
 
 }  // namespace chromeos