Remove the dependence on BrowserThread::FILE for

android_webview/browser/aw_browser_context.cc

 // Copyright (c) 2012 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 "android_webview/browser/aw_browser_context.h"
 
 #include <utility>
 
 #include "android_webview/browser/aw_browser_policy_connector.h"
 #include "android_webview/browser/aw_form_database_service.h"
@@ skipping 60 matching lines @@
     // trigger only in case of real errors.
     LOG(WARNING) << "Failed to delete " << path.AsUTF8Unsafe();
   }
 }
 
 AwBrowserContext* g_browser_context = NULL;
 
 std::unique_ptr<net::ProxyConfigService> CreateProxyConfigService() {
   std::unique_ptr<net::ProxyConfigService> config_service =
       net::ProxyService::CreateSystemProxyConfigService(
-          BrowserThread::GetTaskRunnerForThread(BrowserThread::IO),
-          nullptr /* Ignored on Android */);
+          BrowserThread::GetTaskRunnerForThread(BrowserThread::IO));
 
   // TODO(csharrison) Architect the wrapper better so we don't need a cast for
   // android ProxyConfigServices.
   net::ProxyConfigServiceAndroid* android_config_service =
       static_cast<net::ProxyConfigServiceAndroid*>(config_service.get());
   android_config_service->set_exclude_pac_url(true);
   return config_service;
 }
 
 bool OverrideBlacklistForURL(const GURL& url, bool* block, int* reason) {
@@ skipping 315 matching lines @@
 
 void AwBrowserContext::RebuildTable(
     const scoped_refptr<URLEnumerator>& enumerator) {
   // Android WebView rebuilds from WebChromeClient.getVisitedHistory. The client
   // can change in the lifetime of this WebView and may not yet be set here.
   // Therefore this initialization path is not used.
   enumerator->OnComplete(true);
 }
 
 }  // namespace android_webview