Introduce ability to register callback with GoogleURLTracker

chrome/browser/google/google_url_tracker.h

 // 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.
 
 #ifndef CHROME_BROWSER_GOOGLE_GOOGLE_URL_TRACKER_H_
 #define CHROME_BROWSER_GOOGLE_GOOGLE_URL_TRACKER_H_
 
 #include <map>
 #include <string>
 #include <utility>
 
 #include "base/callback_forward.h"
+#include "base/callback_list.h"
 #include "base/gtest_prod_util.h"
 #include "base/memory/scoped_ptr.h"
 #include "base/memory/weak_ptr.h"
 #include "chrome/browser/google/google_url_tracker_map_entry.h"
 #include "components/keyed_service/core/keyed_service.h"
 #include "net/base/network_change_notifier.h"
 #include "net/url_request/url_fetcher.h"
 #include "net/url_request/url_fetcher_delegate.h"
 #include "url/gurl.h"
 
@@ skipping 19 matching lines @@
 // the notification service for NOTIFICATION_GOOGLE_URL_UPDATED, which provides
 // the original and updated values.
 //
 // To protect users' privacy and reduce server load, no updates will be
 // performed (ever) unless at least one consumer registers interest by calling
 // RequestServerCheck().
 class GoogleURLTracker : public net::URLFetcherDelegate,
                          public net::NetworkChangeNotifier::IPAddressObserver,
                          public KeyedService {
  public:
+  // Callback that is called when the Google URL is updated. The arguments are
+  // the old and new URLs.
+  typedef base::Callback<void(GURL, GURL)> OnGoogleURLUpdatedCallback;
+  typedef base::CallbackList<void(GURL, GURL)> CallbackList;
+  typedef CallbackList::Subscription Subscription;
+
   // The contents of the Details for a NOTIFICATION_GOOGLE_URL_UPDATED.
   typedef std::pair<GURL, GURL> UpdatedDetails;
 
   // The constructor does different things depending on which of these values
   // you pass it.  Hopefully these are self-explanatory.
   enum Mode {
     NORMAL_MODE,
     UNIT_TEST_MODE,
   };
 
+  static const char kDefaultGoogleHomepage[];
+  static const char kSearchDomainCheckURL[];
+
   // Only the GoogleURLTrackerFactory and tests should call this.  No code other
   // than the GoogleURLTracker itself should actually use
   // GoogleURLTrackerFactory::GetForProfile().
   GoogleURLTracker(Profile* profile,
                    scoped_ptr<GoogleURLTrackerNavigationHelper> nav_helper,
                    Mode mode);
 
   virtual ~GoogleURLTracker();
 
   // Returns the current Google URL.  This will return a valid URL even if
@@ skipping 46 matching lines @@
   // Called by the navigation observer once a load we're watching commits.
   // |infobar_service| is the same as for OnNavigationPending();
   // |search_url| is guaranteed to be valid.
   virtual void OnNavigationCommitted(InfoBarService* infobar_service,
                                      const GURL& search_url);
 
   // Called by the navigation observer when a tab closes.
   virtual void OnTabClosed(
       content::NavigationController* navigation_controller);
 
-  static const char kDefaultGoogleHomepage[];
-  static const char kSearchDomainCheckURL[];
+  scoped_ptr<Subscription> RegisterCallback(
+      const OnGoogleURLUpdatedCallback& cb);
 
  private:
   friend class GoogleURLTrackerTest;
 
   typedef std::map<const InfoBarService*, GoogleURLTrackerMapEntry*> EntryMap;
 
   // net::URLFetcherDelegate:
   virtual void OnURLFetchComplete(const net::URLFetcher* source) OVERRIDE;
 
   // NetworkChangeNotifier::IPAddressObserver:
@@ skipping 28 matching lines @@
   // Unregisters any listeners for the navigation controller in |map_entry|.
   // This sanity-DCHECKs that these are registered (or not) in the specific
   // cases we expect.  (|must_be_listening_for_commit| is used purely for this
   // sanity-checking.)  This also unregisters the global navigation pending
   // listener if there are no remaining listeners for navigation commits, as we
   // no longer need them until another search is committed.
   void UnregisterForEntrySpecificNotifications(
       const GoogleURLTrackerMapEntry& map_entry,
       bool must_be_listening_for_commit);
 
+  void NotifyGoogleURLUpdated(GURL old_url, GURL new_url);
+
+  CallbackList callback_list_;
+
   Profile* profile_;
 
   scoped_ptr<GoogleURLTrackerNavigationHelper> nav_helper_;
 
   // Creates an infobar and adds it to the provided InfoBarService.  Returns the
   // infobar on success or NULL on failure.  The caller does not own the
   // returned object, the InfoBarService does.
   base::Callback<
       infobars::InfoBar*(InfoBarService*, GoogleURLTracker*, const GURL&)>
       infobar_creator_;
@@ skipping 16 matching lines @@
                            // nor the last prompted Google URL.
   bool search_committed_;  // True when we're expecting a notification of a new
                            // pending search navigation.
   EntryMap entry_map_;
   base::WeakPtrFactory<GoogleURLTracker> weak_ptr_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(GoogleURLTracker);
 };
 
 #endif  // CHROME_BROWSER_GOOGLE_GOOGLE_URL_TRACKER_H_