Notify DataUseTabModel of navigations and tab closures

chrome/browser/android/data_usage/data_use_ui_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_UI_TAB_MODEL_H_
 #define CHROME_BROWSER_ANDROID_DATA_USAGE_DATA_USE_UI_TAB_MODEL_H_
 
 #include <stdint.h>
 
 #include <string>
-#include <unordered_map>
 
+#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/weak_ptr.h"
+#include "base/single_thread_task_runner.h"
 #include "base/threading/thread_checker.h"
+#include "chrome/browser/android/data_usage/data_use_tab_model.h"
 #include "components/keyed_service/core/keyed_service.h"
 #include "ui/base/page_transition_types.h"
 
 class GURL;
 
 namespace chrome {
 
 namespace android {
 
 // DataUseUITabModel tracks data use tracking start and end transitions on the
@@ skipping 32 matching lines @@
                                         const std::string& package_name);
 
   // Returns true if data use tracking has been started for the tab with id
   // |tab_id|. Calling this function resets the state of the tab.
   bool HasDataUseTrackingStarted(int32_t tab_id);
 
   // Returns true if data use tracking has ended for the tab with id |tab_id|.
   // Calling this function resets the state of the tab.
   bool HasDataUseTrackingEnded(int32_t tab_id);
 
+  // Sets the weak pointer to DataUseTabModel that can be used on IO thread.
+  // Should be called at most once.
+  void SetIODataUseTabModel(base::WeakPtr<DataUseTabModel> data_use_tab_model);

[sclittle, 2015/11/18 21:42:04]

nit: pass in a const base::WeakPtr<DataUseTabModel>& to avoid an extra copy
operation.

[tbansal1, 2015/11/19 00:47:07]

Done. Made the CreateTabObserverOnIOThread a static function as mmenke had
suggested.

+
+  // Notifies |this| of starting and ending of data tracking for tab with id
+  // |tab_id|.
+  void NotifyTrackingStarting(int32_t tab_id);
+  void NotifyTrackingEnding(int32_t tab_id);
+
+  class TabObserverOnIOThread;

[sclittle, 2015/11/18 21:42:04]

nit: Can this be moved to private?

[tbansal1, 2015/11/19 00:47:07]

No, CreateTabObserverOnIOThread in .cc file needs this.

+
  private:
+  // Friends for testing.
+  friend class DataUseUITabModelTest;
   FRIEND_TEST_ALL_PREFIXES(DataUseUITabModelTest, EntranceExitState);
+  FRIEND_TEST_ALL_PREFIXES(DataUseUITabModelTest, ConvertTransitionType);
+  FRIEND_TEST_ALL_PREFIXES(DataUseUITabModelTest, ReportTabEventsTest);
 
   // DataUseTrackingEvent indicates the state of a tab.
   enum DataUseTrackingEvent {
     // Indicates that data use tracking has started.
     DATA_USE_TRACKING_STARTED,
 
     // Indicates that data use tracking has ended.
     DATA_USE_TRACKING_ENDED,
   };
 
-  typedef std::unordered_map<int32_t, DataUseTrackingEvent> TabEvents;
+  typedef base::hash_map<int32_t, DataUseTrackingEvent> TabEvents;
 
-  // DataUseTabModel::Observer implementation:
-  // TODO(tbansal): Add override once DataUseTabModel is checked in.
-  void OnTrackingStarted(int32_t tab_id);
-  void OnTrackingEnded(int32_t tab_id);
+  void SetTabDataUseObserver(
+      scoped_refptr<TabObserverOnIOThread> tab_data_use_observer);
 
   // Creates |event| for tab with id |tab_id| and value |event|, if there is no
   // existing entry for |tab_id|, and returns true. Otherwise, returns false
   // without modifying the entry.
   bool MaybeCreateTabEvent(int32_t tab_id, DataUseTrackingEvent event);
 
   // Removes event entry for |tab_id|, if the entry is equal to |event|, and
   // returns true. Otherwise, returns false without modifying the entry.
   bool RemoveTabEvent(int32_t tab_id, DataUseTrackingEvent event);
 
+  // Converts |page_transition| to DataUseTabModel::TransitionType enum.
+  // Returns true if conversion was successful, and updates |transition_type|.
+  // Otherwise, returns false, and |transition_type| is not changed.
+  // |transition_type| must not be null.
+  bool ConvertTransitionType(
+      ui::PageTransition page_transition,
+      DataUseTabModel::TransitionType* transition_type) const;
+
+  // |tab_data_use_observer_| notifies |this| of starting and ending of data
+  // tracking.

[sclittle, 2015/11/18 21:42:04]

nit: Could you also mention here that it should only be used on the IO thread?

[tbansal1, 2015/11/19 00:47:07]

Done.

+  scoped_refptr<TabObserverOnIOThread> tab_data_use_observer_;
+
   // |tab_events_| stores tracking events of multiple tabs.
   TabEvents tab_events_;
 
-  // |io_task_runner_| accesses DataUseTabModel members on IO thread.
+  // |io_data_use_tab_model_| is notified by |this| about browser navigations
+  // and tab closures on IO thread. |io_data_use_tab_model_| should only be
+  // used on IO thread.
+  base::WeakPtr<DataUseTabModel> io_data_use_tab_model_;
+
   scoped_refptr<base::SingleThreadTaskRunner> io_task_runner_;
+  scoped_refptr<base::SingleThreadTaskRunner> ui_task_runner_;
 
   base::ThreadChecker thread_checker_;
 
+  base::WeakPtrFactory<DataUseUITabModel> weak_factory_;
+
   DISALLOW_COPY_AND_ASSIGN(DataUseUITabModel);
 };
 
 }  // namespace android
 
 }  // namespace chrome
 
 #endif  // CHROME_BROWSER_ANDROID_DATA_USAGE_DATA_USE_UI_TAB_MODEL_H_