Don't attempt to unload the same extension twice if multiple ExtensionHost instances existed for th…

chrome/browser/extensions/extension_service.h

Index: chrome/browser/extensions/extension_service.h
diff --git a/chrome/browser/extensions/extension_service.h b/chrome/browser/extensions/extension_service.h
index eaf9af2547b37dd1fdf4e9c0a657da0801be8331..9d48d6242998fdf91ac3703ca514c58ab752d17f 100644
--- a/chrome/browser/extensions/extension_service.h
+++ b/chrome/browser/extensions/extension_service.h
@@ -809,6 +809,10 @@ class ExtensionService
   // avoid showing a "new install" notice for an extension reinstall.
   std::set<std::string> extensions_being_reloaded_;
 
+  // A set of the extension ids currently being terminated. We use this to
+  // avoid trying to unload the same extension twice.
+  std::set<std::string> extensions_being_terminated_;
+
   scoped_ptr<ExtensionErrorUI> extension_error_ui_;
   // Sequenced task runner for extension related file operations.
   scoped_refptr<base::SequencedTaskRunner> file_task_runner_;