Tabs API is usable without tabs permission.

chrome/browser/extensions/browser_event_router.cc

 // Copyright (c) 2012 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/extensions/browser_event_router.h"
 
 #include "base/json/json_writer.h"
 #include "base/values.h"
 #include "chrome/browser/extensions/api/extension_action/extension_page_actions_api_constants.h"
 #include "chrome/browser/extensions/api/tabs/tabs_constants.h"
@@ skipping 366 matching lines @@
       event_name, event_args.Pass(), profile, cross_incognito_args.Pass(),
       GURL());
 }
 
 void BrowserEventRouter::DispatchEventWithTab(
     Profile* profile,
     const std::string& extension_id,
     const char* event_name,
     const WebContents* web_contents,
     bool active,
-    EventRouter::UserGestureState user_gesture) {
+    EventRouter::UserGestureState user_gesture,
+    scoped_ptr<ListValue> event_args) {
   if (!profile_->IsSameProfile(profile))
     return;
 
-  scoped_ptr<ListValue> args(new ListValue());
-  args->Append(ExtensionTabUtil::CreateTabValueActive(
-      web_contents, active));
   if (!extension_id.empty()) {
-    DispatchEventToExtension(profile, extension_id, event_name, args.Pass(),
-                             user_gesture);
+    event_args->Append(ExtensionTabUtil::CreateTabValueActive(
+        web_contents,
+        active,
+        profile->GetExtensionService()->extensions()->GetByID(extension_id)));
+    DispatchEventToExtension(profile, extension_id, event_name,
+                             event_args.Pass(), user_gesture);
   } else {
-    DispatchEvent(profile, event_name, args.Pass(), user_gesture);
+    const EventListenerMap::ListenerList& listeners(
+        ExtensionSystem::Get(profile)->event_router()->
+        listeners().GetEventListenersByName(event_name));
+
+    for (EventListenerMap::ListenerList::const_iterator it = listeners.begin();
+         it != listeners.end();
+         ++it) {
+      scoped_ptr<ListValue> args(event_args->DeepCopy());
+      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);
+    }
   }
 }
 
 void BrowserEventRouter::DispatchSimpleBrowserEvent(
     Profile* profile, const int window_id, const char* event_name) {
   if (!profile_->IsSameProfile(profile))
     return;
 
   scoped_ptr<ListValue> args(new ListValue());
   args->Append(Value::CreateIntegerValue(window_id));
@@ skipping 11 matching lines @@
   // changed.  Send a notification to the extension.
   scoped_ptr<ListValue> args(new ListValue());
 
   // First arg: The id of the tab that changed.
   args->Append(Value::CreateIntegerValue(ExtensionTabUtil::GetTabId(contents)));
 
   // Second arg: An object containing the changes to the tab state.
   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());
 
-  Profile* profile = Profile::FromBrowserContext(contents->GetBrowserContext());
-  DispatchEvent(profile, events::kOnTabUpdated, args.Pass(),
-                EventRouter::USER_GESTURE_UNKNOWN);
+  DispatchEventWithTab(profile, "", events::kOnTabUpdated, contents, true,
+                       EventRouter::USER_GESTURE_UNKNOWN, args.Pass());
 }
 
 BrowserEventRouter::TabEntry* BrowserEventRouter::GetTabEntry(
     const WebContents* contents) {
   int tab_id = ExtensionTabUtil::GetTabId(contents);
   std::map<int, TabEntry>::iterator i = tab_entries_.find(tab_id);
   if (tab_entries_.end() == i)
     return NULL;
   return &i->second;
 }
@@ skipping 139 matching lines @@
     DispatchEventWithTab(profile,
                          extension_action.extension_id(),
                          event_name,
                          tab_contents->web_contents(),
                          true,
                          EventRouter::USER_GESTURE_ENABLED);
   }
 }
 
 }  // namespace extensions