Introduce lock screen app context to extension features

chrome/browser/extensions/extension_service.cc

Index: chrome/browser/extensions/extension_service.cc
diff --git a/chrome/browser/extensions/extension_service.cc b/chrome/browser/extensions/extension_service.cc
index 865438513dd39f0ea0d461506492a3c0736b8112..37045a0e3d52f5acdd4ef9c84c5a5e145c7c06c5 100644
--- a/chrome/browser/extensions/extension_service.cc
+++ b/chrome/browser/extensions/extension_service.cc
@@ -352,6 +352,19 @@ ExtensionService::ExtensionService(Profile* profile,
   registrar_.Add(this,
                  chrome::NOTIFICATION_PROFILE_DESTRUCTION_STARTED,
                  content::Source<Profile>(profile_));
+#if defined(OS_CHROMEOS)
+  // Sign in profile extension service should observe session start - when the
+  // session is started, the context's process map should be updated to consider
+  // extension scripts to run in lock screen context (as the sign-in profile
+  // will be used to host lock screen apps from that point).
+  // TODO(tbarzic): Consider introducing a profile dedicated to lock screen apps
+  //     so the process map's 'is lock screen context' flag does not have to be
+  //     changed when the user session starts.
+  if (chromeos::ProfileHelper::IsSigninProfile(profile_)) {
+    registrar_.Add(this, chrome::NOTIFICATION_SESSION_STARTED,
+                   content::NotificationService::AllSources());
+  }
+#endif
 
   extensions::ExtensionManagementFactory::GetForBrowserContext(profile_)
       ->AddObserver(this);
@@ -2258,6 +2271,20 @@ void ExtensionService::Observe(int type,
       OnProfileDestructionStarted();
       break;
     }
+#if defined(OS_CHROMEOS)
+    case chrome::NOTIFICATION_SESSION_STARTED: {
+      DCHECK(chromeos::ProfileHelper::IsSigninProfile(profile_));
+
+      // When the user session starts, mark the signin context as lock screen
+      // context, as it will be used to host apps on lock screen.
+      extensions::ProcessMap::Get(profile_)->set_is_lock_screen_context(true);
+      BrowserThread::PostTask(
+          BrowserThread::IO, FROM_HERE,
+          base::BindOnce(&extensions::InfoMap::SetIsLockScreenContext,
+                         system_->info_map(), true));
+      break;
+    }
+#endif
 
     default:
       NOTREACHED() << "Unexpected notification type.";