chrome.tabs.onUpdated doesn't called with 'loading' twice.

chrome/browser/extensions/api/tabs/tabs_event_router.h

 // Copyright 2013 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.
 
 #ifndef CHROME_BROWSER_EXTENSIONS_API_TABS_TABS_EVENT_ROUTER_H_
 #define CHROME_BROWSER_EXTENSIONS_API_TABS_TABS_EVENT_ROUTER_H_
 
 #include <map>
 #include <string>
 
@@ skipping 130 matching lines @@
   //  - distinguish between tab creation and tab insertion
   //  - not send tab-detached after tab-removed
   //  - reduce the "noise" of TabChangedAt() when sending events to extensions
   class TabEntry {
    public:
     // Create a new tab entry whose initial state is TAB_COMPLETE.  This
     // constructor is required because TabEntry objects placed inside an
     // std::map<> by value.
     TabEntry();
 
-    // Update the load state of the tab based on its WebContents.  Returns true
-    // if the state changed, false otherwise.  Whether the state has changed or
-    // not is used to determine if events needs to be sent to extensions during
-    // processing of TabChangedAt(). This method will "hold" a state-change
-    // to "loading", until the DidNavigate() method which should always follow
-    // it. Returns NULL if no updates should be sent.
-    base::DictionaryValue* UpdateLoadState(
+    // Update 'complete' state baed on its WebContents.
+    scoped_ptr<base::DictionaryValue> UpdateComplete(
         const content::WebContents* contents);
 
-    // Indicates that a tab load has resulted in a navigation and the
-    // destination url is available for inspection. Returns NULL if no updates
-    // should be sent.
-    base::DictionaryValue* DidNavigate(const content::WebContents* contents);
+    // Detect what has changed by holding onto the previous values.
+    scoped_ptr<base::DictionaryValue> Update(
+        const content::WebContents* contents);
 
    private:
     // Whether we are waiting to fire the 'complete' status change. This will
     // occur the first time the WebContents stops loading after the
     // NAV_ENTRY_COMMITTED was fired. The tab may go back into and out of the
     // loading state subsequently, but we will ignore those changes.
     bool complete_waiting_on_load_;
 
     GURL url_;
   };
 
   // Gets the TabEntry for the given |contents|. Returns TabEntry* if
   // found, NULL if not.
   TabEntry* GetTabEntry(content::WebContents* contents);
 
   std::map<int, TabEntry> tab_entries_;
 
   // The main profile that owns this event router.
   Profile* profile_;
 
   ScopedObserver<favicon::FaviconDriver, TabsEventRouter>
       favicon_scoped_observer_;
 
   DISALLOW_COPY_AND_ASSIGN(TabsEventRouter);
 };
 
 }  // namespace extensions
 
 #endif  // CHROME_BROWSER_EXTENSIONS_API_TABS_TABS_EVENT_ROUTER_H_