[Downloads] Remove externally deleted items from downloads history

chrome/browser/android/download/download_manager_service.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/android/download/download_manager_service.h"
 
 #include "base/android/jni_string.h"
 #include "base/location.h"
 #include "base/single_thread_task_runner.h"
 #include "base/threading/thread_task_runner_handle.h"
@@ skipping 155 matching lines @@
   }
 
   Java_DownloadManagerService_onAllDownloadsRetrieved(
       env, java_ref_, j_download_item_list, is_off_the_record);
 }
 
 void DownloadManagerService::CheckForExternallyRemovedDownloads(
     JNIEnv* env,
     const JavaParamRef<jobject>& obj,
     bool is_off_the_record) {
+  // Once the history query is complete, download_history.cc will check for the
+  // removal of history files. If the history query is not yet complete, ignore
+  // requests to check for externally removed downloads.
+  if (!is_history_query_complete_)
+    return;
+
   content::DownloadManager* manager = GetDownloadManager(is_off_the_record);
   if (!manager)
     return;
   manager->CheckForHistoryFilesRemoval();
 }
 
 void DownloadManagerService::CancelDownload(
     JNIEnv* env,
     jobject obj,
     const JavaParamRef<jstring>& jdownload_guid,
@@ skipping 197 matching lines @@
   content::DownloadManager* manager =
       content::BrowserContext::GetDownloadManager(profile);
 
   // Update notifiers to monitor any newly created DownloadManagers.
   updateNotifier(
       this, manager,
       is_off_the_record ? off_the_record_notifier_ : original_notifier_);
 
   return manager;
 }