Ensure tests have an active task runner

chrome/browser/lifetime/application_lifetime.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/lifetime/application_lifetime.h"
 
 #include "base/bind.h"
 #include "base/command_line.h"
 #include "base/logging.h"
 #include "base/memory/scoped_ptr.h"
@@ skipping 64 matching lines @@
   // Check TabsNeedBeforeUnloadFired().
   for (; !browser_it.done(); browser_it.Next()) {
     if (browser_it->TabsNeedBeforeUnloadFired())
       return false;
   }
   return true;
 }
 #endif  // !defined(OS_ANDROID)
 
 int g_keep_alive_count = 0;
+bool g_disable_shutdown_for_testing = false;
 
 #if defined(OS_CHROMEOS)
 // Whether chrome should send stop request to a session manager.
 bool g_send_stop_request_to_session_manager = false;
 #endif
 
 }  // namespace
 
 void MarkAsCleanShutdown() {
   // TODO(beng): Can this use ProfileManager::GetLoadedProfiles() instead?
@@ skipping 230 matching lines @@
 
   DCHECK(g_browser_process);
   // Although we should have a browser process, if there is none,
   // there is nothing to do.
   if (!g_browser_process) return;
 
   // Allow the app to shutdown again.
   if (!WillKeepAlive()) {
     g_browser_process->ReleaseModule();
     // If there are no browsers open and we aren't already shutting down,
-    // initiate a shutdown. Also skips shutdown if this is a unit test
-    // (MessageLoop::current() == null).
+    // initiate a shutdown. Also skips shutdown if this is a unit test.
+    // (MessageLoop::current() == null or explicitly disabled).
     if (chrome::GetTotalBrowserCount() == 0 &&
-        !browser_shutdown::IsTryingToQuit() &&
-        base::MessageLoop::current()) {
+        !browser_shutdown::IsTryingToQuit() && base::MessageLoop::current() &&
+        !g_disable_shutdown_for_testing) {
       CloseAllBrowsers();
     }
   }
 }
 
 bool WillKeepAlive() {
   return g_keep_alive_count > 0;
 }
 
 void NotifyAppTerminating() {
@@ skipping 65 matching lines @@
   // 2. If the desktop type of the browser going away is desktop and the ASH
   //    environment is still active.
   if (browser->host_desktop_type() == chrome::HOST_DESKTOP_TYPE_NATIVE)
     return !ash::Shell::HasInstance();
   else if (browser->host_desktop_type() == chrome::HOST_DESKTOP_TYPE_ASH)
     return BrowserList::GetInstance(chrome::HOST_DESKTOP_TYPE_NATIVE)->empty();
 #endif
   return true;
 }
 
+void DisableShutdownForTesting(bool disable_shutdown_for_testing) {
+  g_disable_shutdown_for_testing = disable_shutdown_for_testing;

[Andrew T Wilson (Slow), 2015/04/27 09:48:26]

Should setting this to false also initiate a shutdown using the same criteria as
DecrementKeepAliveCount()?

[Sami, 2015/04/27 11:31:40]

That's a good thought, but unfortunately in BackgroundModeManagerTest it leads
back to the original problem since at the time of this call we don't have the
necessary context to do a proper shutdown (e.g., no MessageCenter instance).

I've now changed this to perform the shutdown like you suggested, but also made
BackgroundModeManagerTest ensure that we don't try to close the browser when we
shouldn't.

+}
+
 }  // namespace chrome