History: Fix flicker of sync notices when loading new data

chrome/browser/ui/webui/browsing_history_handler.cc

 // 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.
 
 #include "chrome/browser/ui/webui/browsing_history_handler.h"
 
 #include <stddef.h>
 
 #include <set>
 #include <utility>
@@ skipping 400 matching lines @@
   history::WebHistoryService* web_history =
       WebHistoryServiceFactory::GetForProfile(Profile::FromWebUI(web_ui()));
   if (web_history) {
     DCHECK(!web_history_service_observer_.IsObserving(web_history));
     web_history_service_observer_.Add(web_history);
     sync_service_observer_.RemoveAll();
   }
 }
 
 void BrowsingHistoryHandler::WebHistoryTimeout() {
+  has_synced_results_ = false;
   // TODO(dubroy): Communicate the failure to the front end.
   if (!query_task_tracker_.HasTrackedTasks())
     ReturnResultsToFrontEnd();
 
   UMA_HISTOGRAM_ENUMERATION(
       "WebHistory.QueryCompletion",
       WEB_HISTORY_QUERY_TIMED_OUT, NUM_WEB_HISTORY_QUERY_BUCKETS);
 }
 
 void BrowsingHistoryHandler::QueryHistory(
     const base::string16& search_text,
     const history::QueryOptions& options) {
   Profile* profile = Profile::FromWebUI(web_ui());
 
   // Anything in-flight is invalid.
   query_task_tracker_.TryCancelAll();
   web_history_request_.reset();
 
   query_results_.clear();
   results_info_value_.Clear();
-  has_synced_results_ = false;
-  has_other_forms_of_browsing_history_ = false;
 
   history::HistoryService* hs = HistoryServiceFactory::GetForProfile(
       profile, ServiceAccessType::EXPLICIT_ACCESS);
   hs->QueryHistory(search_text,
                    options,
                    base::Bind(&BrowsingHistoryHandler::QueryComplete,
                               base::Unretained(this),
                               search_text,
                               options),
                    &query_task_tracker_);
@@ skipping 21 matching lines @@
     // Test the existence of other forms of browsing history.
     browsing_data::ShouldShowNoticeAboutOtherFormsOfBrowsingHistory(
         ProfileSyncServiceFactory::GetInstance()->GetForProfile(profile),
         web_history,
         base::Bind(
             &BrowsingHistoryHandler::OtherFormsOfBrowsingHistoryQueryComplete,
             weak_factory_.GetWeakPtr()));
   } else {
     // The notice could not have been shown, because there is no web history.
     RecordMetricsForNoticeAboutOtherFormsOfBrowsingHistory(false);
+    has_synced_results_ = false;
+    has_other_forms_of_browsing_history_ = false;
   }
 }
 
 void BrowsingHistoryHandler::HandleQueryHistory(const base::ListValue* args) {
   history::QueryOptions options;
 
   // Parse the arguments from JavaScript. There are five required arguments:
   // - the text to search for (may be empty)
   // - the offset from which the search should start (in multiples of week or
   //   month, set by the next argument).
@@ skipping 510 matching lines @@
     bool expired,
     const history::URLRows& deleted_rows,
     const std::set<GURL>& favicon_urls) {
   if (all_history || DeletionsDiffer(deleted_rows, urls_to_be_deleted_))
     web_ui()->CallJavascriptFunctionUnsafe("historyDeleted");
 }
 
 void BrowsingHistoryHandler::OnWebHistoryDeleted() {
   web_ui()->CallJavascriptFunctionUnsafe("historyDeleted");
 }