Remove one thread hop while fetching matching rules

chrome/browser/android/data_usage/data_use_tab_model.h

 // Copyright 2015 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_ANDROID_DATA_USAGE_DATA_USE_TAB_MODEL_H_
 #define CHROME_BROWSER_ANDROID_DATA_USAGE_DATA_USE_TAB_MODEL_H_
 
 #include <stddef.h>
 
 #include <string>
 #include <vector>
 
 #include "base/containers/hash_tables.h"
 #include "base/gtest_prod_util.h"
 #include "base/macros.h"
-#include "base/memory/ref_counted.h"
 #include "base/memory/scoped_ptr.h"
 #include "base/memory/weak_ptr.h"
 #include "base/observer_list.h"
 #include "base/threading/thread_checker.h"
 #include "base/time/time.h"
 #include "chrome/browser/android/data_usage/tab_data_use_entry.h"
 #include "components/sessions/core/session_id.h"
+#include "url/gurl.h"
 
 namespace base {
 class SingleThreadTaskRunner;
 class TickClock;
 }
 
-class GURL;
-
 namespace chrome {
 
 namespace android {
 
 class DataUseMatcher;
-class ExternalDataUseObserver;
+class ExternalDataUseObserverBridge;
 
 // Models tracking and labeling of data usage within each Tab. Within each tab,
 // the model tracks the data use of a sequence of navigations in a "tracking
 // session" beginning with an entry event and ending with an exit event.
 // Typically, these events are navigations matching a URL pattern, or various
 // types of browser-initiated navigations. A single tab may have several
 // disjoint "tracking sessions" depending on the sequence of entry and exit
 // events that took place.
 class DataUseTabModel {
  public:
@@ skipping 30 matching lines @@
 
     // Notification callback when tab tracking sessions are started and ended.
     // The callback will be received on the same thread AddObserver was called
     // from.
     virtual void NotifyTrackingStarting(SessionID::id_type tab_id) = 0;
     virtual void NotifyTrackingEnding(SessionID::id_type tab_id) = 0;
   };
 
   DataUseTabModel();
 
-  // Initializes |this| on UI thread. |external_data_use_observer| is the weak
-  // pointer to ExternalDataUseObserver object that owns |this|.
+  // Initializes |this| on UI thread. |external_data_use_observer_bridge| is the
+  // pointer to ExternalDataUseObserverBridge object. DataUseTabModel and
+  // ExternalDataUseObserverBridge objects are owned by ExternalDataUseObserver
+  // and DataUseTabModel is destroyed first followed by
+  // ExternalDataUseObserverBridge.
   void InitOnUIThread(
-      const scoped_refptr<base::SingleThreadTaskRunner>& io_task_runner,
-      const base::WeakPtr<ExternalDataUseObserver>& external_data_use_observer);
+      const ExternalDataUseObserverBridge* external_data_use_observer_bridge);
 
   virtual ~DataUseTabModel();
 
   base::WeakPtr<DataUseTabModel> GetWeakPtr();
 
   // Notifies the DataUseTabModel of navigation events. |tab_id| is the source
   // tab of the generated event, |transition| indicates the type of the UI
   // event/transition,  |url| is the URL in the source tab, |package| indicates
   // the android package name of external application that initiated the event.
   void OnNavigationEvent(SessionID::id_type tab_id,
@@ skipping 160 matching lines @@
   base::WeakPtrFactory<DataUseTabModel> weak_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(DataUseTabModel);
 };
 
 }  // namespace android
 
 }  // namespace chrome
 
 #endif  // CHROME_BROWSER_ANDROID_DATA_USAGE_DATA_USE_TAB_MODEL_H_