[ios] Wait for sync query to return before displaying history

ios/chrome/browser/ui/history/history_service_facade.mm

 // Copyright 2016 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.
 
 #import "ios/chrome/browser/ui/history/history_service_facade.h"
 
 #include <stddef.h>
 
 #include "base/bind.h"
 #include "base/bind_helpers.h"
@@ skipping 60 matching lines @@
 
 }  // namespace
 
 #pragma mark - QueryResult
 
 HistoryServiceFacade::QueryResult::QueryResult()
     : query(base::string16()),
       query_start_time(base::string16()),
       query_end_time(base::string16()),
       finished(false),
+      sync_returned(false),
       has_synced_results(false),
       sync_finished(false),
       entries(std::vector<history::HistoryEntry>()) {}
 
 HistoryServiceFacade::QueryResult::QueryResult(const QueryResult& other) =
     default;
 
 HistoryServiceFacade::QueryResult::~QueryResult() {}
 
 #pragma mark - RemovedEntry
@@ skipping 42 matching lines @@
 void HistoryServiceFacade::QueryHistory(const base::string16& search_text,
                                         const history::QueryOptions& options) {
   // Anything in-flight is invalid.
   query_task_tracker_.TryCancelAll();
   web_history_request_.reset();
 
   // Reset results.
   query_results_.clear();
   results_info_value_ = QueryResult();
 
-  // Query local history.
-  history::HistoryService* history_service =
-      ios::HistoryServiceFactory::GetForBrowserState(
-          browser_state_, ServiceAccessType::EXPLICIT_ACCESS);
-  if (history_service) {
-    history_service->QueryHistory(
-        search_text, options,
-        base::Bind(&HistoryServiceFacade::QueryComplete, base::Unretained(this),
-                   search_text, options),
-        &query_task_tracker_);
-  }
-
   // Query synced history.
   history::WebHistoryService* web_history =
       ios::WebHistoryServiceFactory::GetForBrowserState(browser_state_);
   if (web_history) {
     web_history_query_results_.clear();
     web_history_request_ = web_history->QueryHistory(
         search_text, options,
         base::Bind(&HistoryServiceFacade::WebHistoryQueryComplete,
                    base::Unretained(this), search_text, options,
                    base::TimeTicks::Now()));
     // Start a timer so we know when to give up.
     web_history_timer_.Start(
         FROM_HERE, base::TimeDelta::FromSeconds(kWebHistoryTimeoutSeconds),
         this, &HistoryServiceFacade::WebHistoryTimeout);
   }
+
+  // Query local history.
+  history::HistoryService* history_service =
+      ios::HistoryServiceFactory::GetForBrowserState(
+          browser_state_, ServiceAccessType::EXPLICIT_ACCESS);
+  if (history_service) {
+    history_service->QueryHistory(
+        search_text, options,
+        base::Bind(&HistoryServiceFacade::QueryComplete, base::Unretained(this),
+                   search_text, options),
+        &query_task_tracker_);
+  }
 }
 
 void HistoryServiceFacade::RemoveHistoryEntries(
     const std::vector<RemovedEntry>& entries) {
   // Early return if there is a deletion in progress.
   if (delete_task_tracker_.HasTrackedTasks() || has_pending_delete_request_) {
     return;
   }
 
   history::HistoryService* history_service =
@@ skipping 187 matching lines @@
 
         web_history_query_results_.push_back(history::HistoryEntry(
             history::HistoryEntry::REMOTE_ENTRY, gurl, title, time, client_id,
             !search_text.empty(), base::string16(),
             /* blocked_visit */ false));
       }
     }
   }
 
   results_info_value_.has_synced_results = results_value != NULL;
+  results_info_value_.sync_returned = true;
   if (results_value) {
     std::string continuation_token;
     results_value->GetString("continuation_token", &continuation_token);
     results_info_value_.sync_finished = continuation_token.empty();
   }
   if (!query_task_tracker_.HasTrackedTasks())
     ReturnResultsToFrontEnd();
 }
 
 void HistoryServiceFacade::RemoveComplete() {
@@ skipping 67 matching lines @@
     const history::URLRows& deleted_rows,
     const std::set<GURL>& favicon_urls) {
   if (all_history || DeletionsDiffer(deleted_rows, urls_to_be_deleted_)) {
     if ([delegate_
             respondsToSelector:
                 @selector(historyServiceFacadeDidObserveHistoryDeletion:)]) {
       [delegate_ historyServiceFacadeDidObserveHistoryDeletion:this];
     }
   }
 }