Allow MessageFilters to restrict listening to specific message classes

extensions/browser/extension_message_filter.cc

Index: extensions/browser/extension_message_filter.cc
diff --git a/extensions/browser/extension_message_filter.cc b/extensions/browser/extension_message_filter.cc
index 3a1c0d23ea3a58d850f5c070669760cf4f6a138e..c9222f8db4b6f6827e3386eb0103df2b750869af 100644
--- a/extensions/browser/extension_message_filter.cc
+++ b/extensions/browser/extension_message_filter.cc
@@ -17,10 +17,18 @@ using content::BrowserThread;
 using content::RenderProcessHost;
 
 namespace extensions {
+namespace {
+const uint32 kFilteredMessageClasses[] = {
+  ExtensionMsgStart
+};
+}  // namespace
 
 ExtensionMessageFilter::ExtensionMessageFilter(int render_process_id,
                                                content::BrowserContext* context)
-    : render_process_id_(render_process_id), browser_context_(context) {
+    : BrowserMessageFilter(
+          kFilteredMessageClasses, arraysize(kFilteredMessageClasses)),
+      render_process_id_(render_process_id),
+      browser_context_(context) {
   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
 }