Mustash: Ignore --mash flag when comparing flags in UserSessionManager.

chrome/browser/chromeos/login/session/user_session_manager.cc

Index: chrome/browser/chromeos/login/session/user_session_manager.cc
diff --git a/chrome/browser/chromeos/login/session/user_session_manager.cc b/chrome/browser/chromeos/login/session/user_session_manager.cc
index b065b22c4e183986ee9b4b70ab037256704b1dc1..6c6b6c440713dd8a4c68a77819884a91615ff2c3 100644
--- a/chrome/browser/chromeos/login/session/user_session_manager.cc
+++ b/chrome/browser/chromeos/login/session/user_session_manager.cc
@@ -77,6 +77,7 @@
 #include "chrome/browser/ui/app_list/app_list_service.h"
 #include "chrome/browser/ui/ash/ash_util.h"
 #include "chrome/browser/ui/startup/startup_browser_creator.h"
+#include "chrome/common/channel_info.h"
 #include "chrome/common/chrome_switches.h"
 #include "chrome/common/logging_chrome.h"
 #include "chrome/common/pref_names.h"
@@ -107,6 +108,7 @@
 #include "components/user_manager/user_manager.h"
 #include "components/user_manager/user_names.h"
 #include "components/user_manager/user_type.h"
+#include "components/version_info/version_info.h"
 #include "content/public/browser/browser_thread.h"
 #include "content/public/browser/notification_service.h"
 #include "content/public/browser/storage_partition.h"
@@ -284,12 +286,37 @@ bool NeedRestartToApplyPerSessionFlags(
   if (user_manager::UserManager::Get()->IsLoggedInAsSupervisedUser())
     return false;
 
+  // When running Mus+ash, the flags stored in Profile Prefs will contain
+  // --mash, while the browser command line will not (and should not) have
+  // it, so ignore it for the purpose of comparison.
+  // TODO(mfomitchev): Find a better way. crbug.com/690083
+  bool in_mash = false;
+  base::CommandLine user_flags_no_mash = user_flags;
+
+#if BUILDFLAG(ENABLE_PACKAGE_MASH_SERVICES)
+  in_mash = user_flags.HasSwitch(::switches::kMash);
+  if (in_mash) {
+    base::CommandLine::SwitchMap switches = user_flags.GetSwitches();
+    switches.erase(::switches::kMash);
+    user_flags_no_mash = base::CommandLine(user_flags.GetProgram());
+    for (const std::pair<std::string, base::CommandLine::StringType>& sw :
+         switches) {
+      user_flags_no_mash.AppendSwitchNative(sw.first, sw.second);
+    }
+  }
+#endif  // BUILDFLAG(ENABLE_PACKAGE_MASH_SERVICES)
+
   if (about_flags::AreSwitchesIdenticalToCurrentCommandLine(
-          user_flags, *base::CommandLine::ForCurrentProcess(),
+          user_flags_no_mash, *base::CommandLine::ForCurrentProcess(),
           out_command_line_difference)) {
     return false;
   }
 
+  // TODO(mfomitchev): Browser restart doesn't currently work in Mus+ash.
+  // So if we are running Mustash and we need to restart - just crash right
+  // here. crbug.com/690140
+  CHECK(!in_mash);
+
   return true;
 }