Remove one thread hop while fetching matching rules

chrome/browser/android/data_usage/external_data_use_observer.h

Index: chrome/browser/android/data_usage/external_data_use_observer.h
diff --git a/chrome/browser/android/data_usage/external_data_use_observer.h b/chrome/browser/android/data_usage/external_data_use_observer.h
index ec9c92b00aaeb1b6fa4e79f87594ea7c24ff623e..af89fdbf03eaa337b44b665bdbe7720ba527b702 100644
--- a/chrome/browser/android/data_usage/external_data_use_observer.h
+++ b/chrome/browser/android/data_usage/external_data_use_observer.h
@@ -82,17 +82,21 @@ class ExternalDataUseObserver : public data_usage::DataUseAggregator::Observer {
   // successfully submitted to the external data use observer by Java.
   void OnReportDataUseDone(bool success);
 
-  // Called by DataUseMatcher. |should_register| is true if |this| should
-  // register as a data use observer.
+  // Called by ExternalDataUseObserverBridge. |should_register| is true if
+  // |this| should register as a data use observer.
   void ShouldRegisterAsDataUseObserver(bool should_register);
 
   // Fetches the matching rules asynchronously.
   void FetchMatchingRules();
 
+  // Notifies ExternalDataUseObserver that matching rules have been fetched.
+  void OnFetchMatchingRulesDone();
+
   base::WeakPtr<ExternalDataUseObserver> GetWeakPtr();
 
  private:
   friend class DataUseTabModelTest;
+  friend class DataUseUITabModelTest;
   friend class ExternalDataUseObserverTest;
   FRIEND_TEST_ALL_PREFIXES(ExternalDataUseObserverTest, BufferDataUseReports);
   FRIEND_TEST_ALL_PREFIXES(ExternalDataUseObserverTest, BufferSize);