Make BrowsingDataHandler observe WebHistoryService deletions

chrome/browser/ui/webui/browsing_history_handler.h

Index: chrome/browser/ui/webui/browsing_history_handler.h
diff --git a/chrome/browser/ui/webui/browsing_history_handler.h b/chrome/browser/ui/webui/browsing_history_handler.h
index 8c297d55e08cdf73dbf6c066873f311388aa76c9..dd2a7a5c9c65c24d5a6dbb01e6aa08d42f3e5bd8 100644
--- a/chrome/browser/ui/webui/browsing_history_handler.h
+++ b/chrome/browser/ui/webui/browsing_history_handler.h
@@ -20,6 +20,7 @@
 #include "components/history/core/browser/history_service_observer.h"
 #include "components/history/core/browser/url_row.h"
 #include "components/history/core/browser/web_history_service.h"
+#include "components/sync/driver/sync_service_observer.h"
 #include "content/public/browser/web_ui_message_handler.h"
 #include "url/gurl.h"
 
@@ -36,9 +37,15 @@ struct QueryOptions;
 class QueryResults;
 }
 
+namespace sync_driver {
+class SyncServiceObserver;
+}
+
 // The handler for Javascript messages related to the "history" view.
 class BrowsingHistoryHandler : public content::WebUIMessageHandler,
-                               public history::HistoryServiceObserver {
+                               public history::HistoryServiceObserver,
+                               public history::WebHistoryService::Observer,
+                               public sync_driver::SyncServiceObserver {
  public:
   // Represents a history entry to be shown to the user, representing either
   // a local or remote visit. A single entry can represent multiple visits,
@@ -106,6 +113,9 @@ class BrowsingHistoryHandler : public content::WebUIMessageHandler,
   // WebUIMessageHandler implementation.
   void RegisterMessages() override;
 
+  // SyncServiceObserver implementation.
+  void OnStateChanged() override;
+
   // Handler for the "queryHistory" message.
   void HandleQueryHistory(const base::ListValue* args);
 
@@ -189,6 +199,9 @@ class BrowsingHistoryHandler : public content::WebUIMessageHandler,
                      const history::URLRows& deleted_rows,
                      const std::set<GURL>& favicon_urls) override;
 
+  // history::WebHistoryService::Observer:
+  void OnWebHistoryDeleted() override;
+
   // Tracker for search requests to the history service.
   base::CancelableTaskTracker query_task_tracker_;
 
@@ -217,9 +230,19 @@ class BrowsingHistoryHandler : public content::WebUIMessageHandler,
   // Timer used to implement a timeout on a Web History response.
   base::OneShotTimer web_history_timer_;
 
+  // HistoryService (local history) observer.
   ScopedObserver<history::HistoryService, history::HistoryServiceObserver>
       history_service_observer_;
 
+  // WebHistoryService (synced history) observer.
+  ScopedObserver<history::WebHistoryService,
+                 history::WebHistoryService::Observer>
+      web_history_service_observer_;
+
+  // ProfileSyncService observer listens to late initialization of history sync.
+  ScopedObserver<ProfileSyncService, sync_driver::SyncServiceObserver>
+      sync_service_observer_;
+
   // Whether the last call to Web History returned synced results.
   bool has_synced_results_;