Refactor shutdown code to allow win/linux to run after last browser closes.

chrome/browser/background_contents_service.h

Index: chrome/browser/background_contents_service.h
diff --git a/chrome/browser/background_contents_service.h b/chrome/browser/background_contents_service.h
index 48a9a3ce5c4b011061bd8d65107cc732de40da7d..73d9944b5bf2a8da5f6b1ad6364bd2115ae65175 100644
--- a/chrome/browser/background_contents_service.h
+++ b/chrome/browser/background_contents_service.h
@@ -108,6 +108,10 @@ class BackgroundContentsService : private NotificationObserver {
   typedef std::map<string16, BackgroundContentsInfo> BackgroundContentsMap;
   BackgroundContentsMap contents_map_;
 
+  // If true, should always keep the browser process alive regardless of whether
+  // there are any BackgroundContents (used for manual/automated testing).
+  bool always_keep_alive_;
+
   DISALLOW_COPY_AND_ASSIGN(BackgroundContentsService);
 };