Tabs API is usable without tabs permission.

chrome/browser/extensions/browser_event_router.cc

Index: chrome/browser/extensions/browser_event_router.cc
diff --git a/chrome/browser/extensions/browser_event_router.cc b/chrome/browser/extensions/browser_event_router.cc
index 83347cbb9acf9f55ff020429fed77b14604b7692..66a55629ccf17f0a14965e5e77cb1b0a30a8e9cf 100644
--- a/chrome/browser/extensions/browser_event_router.cc
+++ b/chrome/browser/extensions/browser_event_router.cc
@@ -389,13 +389,29 @@ void BrowserEventRouter::DispatchEventWithTab(
     return;
 
   scoped_ptr<ListValue> args(new ListValue());
-  args->Append(ExtensionTabUtil::CreateTabValueActive(
-      web_contents, active));
   if (!extension_id.empty()) {
+    args->Append(ExtensionTabUtil::CreateTabValueActive(
+        web_contents,
+        active,
+        profile->GetExtensionService()->extensions()->GetByID(extension_id)));
     DispatchEventToExtension(profile, extension_id, event_name, args.Pass(),
                              user_gesture);
   } else {
-    DispatchEvent(profile, event_name, args.Pass(), user_gesture);
+    EventListenerMap::ListenerList listeners(
+        ExtensionSystem::Get(profile)->event_router()->
+        listeners().listeners(event_name));

[Aaron Boodman, 2012/08/30 05:45:48]

The second 'listeners' should be GetListenersByName or some such.

[chebert, 2012/08/30 23:17:20]

Done.

+
+    for (EventListenerMap::ListenerList::iterator it = listeners.begin();
+         it != listeners.end();
+         ++it) {
+      args->Append(ExtensionTabUtil::CreateTabValueActive(
+          web_contents,
+          active,
+          profile->GetExtensionService()->extensions()->GetByID(
+              (*it)->extension_id)));
+      DispatchEventToExtension(profile, (*it)->extension_id, event_name,
+                               args.Pass(), user_gesture);
+    }
   }
 }
 
@@ -427,9 +443,9 @@ void BrowserEventRouter::DispatchTabUpdatedEvent(
   args->Append(changed_properties);
 
   // Third arg: An object containing the state of the tab.
-  args->Append(ExtensionTabUtil::CreateTabValue(contents));
-
   Profile* profile = Profile::FromBrowserContext(contents->GetBrowserContext());
+  args->Append(ExtensionTabUtil::CreateTabValue(contents, NULL /*extension*/));

[Aaron Boodman, 2012/08/30 05:45:48]

Why no extension here?

I think that CreateTabValue() may want to CHECK that it is given an extension to
ensure that we don't accidentally leak info via this function.

[chebert, 2012/08/30 23:17:20]

Done.

+
   DispatchEvent(profile, events::kOnTabUpdated, args.Pass(),
                 EventRouter::USER_GESTURE_UNKNOWN);
 }