Continue browser startup after killing a hung browser instance.

chrome/browser/process_singleton_win.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/process_singleton.h"
 
 #include <windows.h>
 #include <shellapi.h>
 #include <stddef.h>
 
@@ skipping 266 matching lines @@
 
   // Time to take action. Kill the browser process.
   process.Terminate(content::RESULT_CODE_HUNG, true);
   remote_window_ = NULL;
   return PROCESS_NONE;
 }
 
 ProcessSingleton::NotifyResult
 ProcessSingleton::NotifyOtherProcessOrCreate() {
   ProcessSingleton::NotifyResult result = PROCESS_NONE;
-  if (!Create()) {
+  // While the remote window is not functional, attept to create
+  // the Singleton.
+  while (result == PROCESS_NONE && !Create()) {
+    // Process attepts to notify the existing remote window. If the
+    // remote window is fund to be hung, the user is notified and
+    // asked to confirm the termination of the hung window.
     result = NotifyOtherProcess();

[grt (UTC plus 2), 2016/08/24 10:01:26]

this will return PROCESS_NONE if AttemptToNotifyRunningChrome fails for any
reason, not only for hangs. i think it makes sense to retry in these cases, but
not an infloop like this.

this change also removes PROFILE_IN_USE entirely, which doesn't seem right. i
think there are still cases where there's an existing browser process that has
the singleton and isn't (or can't be) terminated.

[gcomanici, 2016/08/25 19:26:07]

The new patch now runs this for the case when the process was hung and killed.
Also, it attempts only once instead of the infinite loop.

-    if (result == PROCESS_NONE)
-      result = PROFILE_IN_USE;
-  } else {
-    g_browser_process->platform_part()->PlatformSpecificCommandLineProcessing(
-        *base::CommandLine::ForCurrentProcess());
   }
+  g_browser_process->platform_part()->PlatformSpecificCommandLineProcessing(

[grt (UTC plus 2), 2016/08/24 10:01:26]

this must only happen when Create() returns true

[gcomanici, 2016/08/25 19:26:07]

Done.

+      *base::CommandLine::ForCurrentProcess());
   return result;
 }
 
 // Look for a Chrome instance that uses the same profile directory. If there
 // isn't one, create a message window with its title set to the profile
 // directory path.
 bool ProcessSingleton::Create() {
   static const wchar_t kMutexName[] = L"Local\\ChromeProcessSingletonStartup!";
 
   remote_window_ = chrome::FindRunningChromeWindow(user_data_dir_);
@@ skipping 49 matching lines @@
   return window_.hwnd() != NULL;
 }
 
 void ProcessSingleton::Cleanup() {
 }
 
 void ProcessSingleton::OverrideShouldKillRemoteProcessCallbackForTesting(
     const ShouldKillRemoteProcessCallback& display_dialog_callback) {
   should_kill_remote_process_callback_ = display_dialog_callback;
 }