Buffer UI navigation events in DataUseTabModel until rule fetch

chrome/browser/android/data_usage/data_use_tab_model.h

Index: chrome/browser/android/data_usage/data_use_tab_model.h
diff --git a/chrome/browser/android/data_usage/data_use_tab_model.h b/chrome/browser/android/data_usage/data_use_tab_model.h
index 2d71ffac0dde7f3d96058f6f58d090ee694ed49b..16e14c7840be9cef02039ed805aa9092a372bafd 100644
--- a/chrome/browser/android/data_usage/data_use_tab_model.h
+++ b/chrome/browser/android/data_usage/data_use_tab_model.h
@@ -193,9 +193,27 @@ class DataUseTabModel {
                            UnexpiredTabEntryRemovaltimeHistogram);
   FRIEND_TEST_ALL_PREFIXES(ExternalDataUseObserverTest,
                            MatchingRuleFetchOnControlAppInstall);
+  FRIEND_TEST_ALL_PREFIXES(ExternalDataUseObserverTest,
+                           ProcessBufferedNavigationEvents);
 
   typedef base::hash_map<SessionID::id_type, TabDataUseEntry> TabEntryMap;
 
+  // Contains the details of a single UI navigation event.
+  struct DataUseUINavigationEvent {

[tbansal1, 2016/03/29 16:20:41]

Methods should come before fields.

[Raj, 2016/03/29 18:03:21]

Done.

+    SessionID::id_type tab_id;

[tbansal1, 2016/03/29 16:20:41]

can these fields be all const?

[Raj, 2016/03/29 18:03:20]

Done.

+    TransitionType transition_type;
+    GURL url;
+    std::string package;
+    DataUseUINavigationEvent(SessionID::id_type tab_id,
+                             TransitionType transition_type,
+                             GURL url,
+                             std::string package)
+        : tab_id(tab_id),
+          transition_type(transition_type),
+          url(url),
+          package(package) {}
+  };
+
   // Gets the current label of a tab, and the new label if a navigation event
   // occurs in the tab. |tab_id| is the source tab of the generated event,
   // |transition| indicates the type of the UI event/transition,  |url| is the
@@ -231,6 +249,8 @@ class DataUseTabModel {
   // size is |kMaxTabEntries|.
   void CompactTabEntries();
 
+  void ProcessBufferedNavigationEvents();

[tbansal1, 2016/03/29 16:20:41]

function comments please.

[Raj, 2016/03/29 18:03:21]

Done.

+
   // Collection of observers that receive tracking session start and end
   // notifications. Notifications are posted on UI thread.
   base::ObserverList<TabDataUseObserver> observers_;
@@ -258,6 +278,15 @@ class DataUseTabModel {
   // True if the external control app is installed.
   bool is_control_app_installed_;
 
+  // Buffers the list of UI navigation events that occurred until the first rule

[tbansal1, 2016/03/29 16:20:41]

s/Buffers the list of/Buffer of/?

[Raj, 2016/03/29 18:03:21]

Done.

+  // fetch is complete or the control app not installed callback was received or
+  // until |kDefaultMaxNavigationEventsBuffered| navigation events were
+  // buffered, whichever occurs first. Existence of the vector in scoped_ptr
+  // indicates if the UI navigation events need to be buffered. If the
+  // scoped_ptr contains a vector all navigation events will be added to it.
+  // Otherwise all navigation events will be processed immediately.
+  scoped_ptr<std::vector<DataUseUINavigationEvent>> data_use_ui_navigations_;
+
   base::ThreadChecker thread_checker_;
 
   base::WeakPtrFactory<DataUseTabModel> weak_factory_;