Preserve hosted apps' background contents across reload

chrome/browser/background_contents_service.cc

 // Copyright (c) 2010 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/background_contents_service.h"
 
 #include "base/basictypes.h"
 #include "base/command_line.h"
 #include "base/string_util.h"
 #include "base/utf_string_conversions.h"
@@ skipping 95 matching lines @@
       BackgroundContentsShutdown(Details<BackgroundContents>(details).ptr());
       break;
     case NotificationType::BACKGROUND_CONTENTS_CLOSED:
       DCHECK(IsTracked(Details<BackgroundContents>(details).ptr()));
       UnregisterBackgroundContents(Details<BackgroundContents>(details).ptr());
       break;
     case NotificationType::BACKGROUND_CONTENTS_NAVIGATED:
       DCHECK(IsTracked(Details<BackgroundContents>(details).ptr()));
       RegisterBackgroundContents(Details<BackgroundContents>(details).ptr());
       break;
-    case NotificationType::EXTENSION_UNLOADED:
-      ShutdownAssociatedBackgroundContents(
-          ASCIIToUTF16(
-              Details<UnloadedExtensionInfo>(details)->extension->id()));
+   case NotificationType::EXTENSION_UNLOADED:
+      switch (Details<UnloadedExtensionInfo>(details)->reason) {
+        case UnloadedExtensionInfo::DISABLE:  // Intentionally fall through.
+        case UnloadedExtensionInfo::UNINSTALL:
+          ShutdownAssociatedBackgroundContents(
+              ASCIIToUTF16(
+                  Details<UnloadedExtensionInfo>(details)->extension->id()));
+            break;
+        case UnloadedExtensionInfo::UPDATE:
+           // Leave BackgroundContents in place
+           break;
+        default:
+           NOTREACHED();

[asargent_no_longer_on_chrome, 2011/01/15 00:09:53]

Would it make sense to shut down the background contents in the default case
here? I'm thinking of the possibility that in the future someone adds a new
reason type to UnloadedExtensionInfo and forgets to update your code here. I.e.
in release builds, where the NOTREACHED won't fire, would we rather err on the
side of the background contents getting shut down than left running? Your call -
just raising it for you to think about. 

[The wrong rickcam account, 2011/01/18 20:08:50]

Done.  I inserted a call to ShutdownAssociatedBackgroundContents immediately
following the NOTREACHED().

+           break;
+      }
       break;
     default:
       NOTREACHED();
       break;
   }
 }
 
 // Loads all background contents whose urls have been stored in prefs.
 void BackgroundContentsService::LoadBackgroundContentsFromPrefs(
     Profile* profile) {
@@ skipping 178 matching lines @@
     TabContents* new_contents,
     WindowOpenDisposition disposition,
     const gfx::Rect& initial_pos,
     bool user_gesture) {
   Browser* browser = BrowserList::GetLastActiveWithProfile(
       new_contents->profile());
   if (!browser)
     return;
   browser->AddTabContents(new_contents, disposition, initial_pos, user_gesture);
 }