Delete the extensions i18n message map when extension unload is received.

chrome/renderer/extensions/dispatcher.cc

Index: chrome/renderer/extensions/dispatcher.cc
diff --git a/chrome/renderer/extensions/dispatcher.cc b/chrome/renderer/extensions/dispatcher.cc
index 49695108dafa9634df4f63d46199086d7a449f4a..a0737a2e23de7cb5eebab3ad48dc0fe57b102693 100644
--- a/chrome/renderer/extensions/dispatcher.cc
+++ b/chrome/renderer/extensions/dispatcher.cc
@@ -16,6 +16,7 @@
 #include "chrome/common/extensions/extension.h"
 #include "chrome/common/extensions/extension_messages.h"
 #include "chrome/common/extensions/manifest.h"
+#include "chrome/common/extensions/message_bundle.h"
 #include "chrome/common/extensions/permissions/permission_set.h"
 #include "chrome/common/url_constants.h"
 #include "chrome/common/view_type.h"
@@ -515,6 +516,10 @@ void Dispatcher::OnUnloaded(const std::string& id) {
 
   v8_context_set_.OnExtensionUnloaded(id);
 
+  // Invalidates the messages map for the extension in case the extension is

[Yoyo Zhou, 2013/03/08 22:17:50]

By the way, the CL description is way too verbose and doesn't get to the point.
You don't need to explain caches from scratch; you can assume the reader has a
basic understanding of Chromium. You can replace lines 2-5 with this, basically,
and include the word "cache" after "message map" in the first line.

Also, it improves readability to put a newline after line 1.

[Patrick Riordan, 2013/03/11 17:32:42]

Done.

+  // reloaded with a new messages map.
+  EraseL10nMessagesMap(id);
+
   // We don't do anything with existing platform-app stylesheets. They will
   // stay resident, but the URL pattern corresponding to the unloaded
   // extension's URL just won't match anything anymore.