Chromium pieces to use the WebKit support for isolation file:// documents in...

chrome/browser/tab_contents/render_view_host_delegate_helper.cc

 // Copyright (c) 2010 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/tab_contents/render_view_host_delegate_helper.h"
 
 #include "base/command_line.h"
 #include "base/string_util.h"
 #include "chrome/browser/browser.h"
 #include "chrome/browser/character_encoding.h"
@@ skipping 170 matching lines @@
     web_prefs.local_storage_enabled =
       !command_line.HasSwitch(switches::kDisableLocalStorage);
     web_prefs.databases_enabled =
       !command_line.HasSwitch(switches::kDisableDatabases);
     web_prefs.experimental_webgl_enabled =
       command_line.HasSwitch(switches::kEnableExperimentalWebGL);
     web_prefs.site_specific_quirks_enabled =
       !command_line.HasSwitch(switches::kDisableSiteSpecificQuirks);
     web_prefs.geolocation_enabled =
       command_line.HasSwitch(switches::kEnableGeolocation);
+    web_prefs.allow_file_access_from_file_urls =
+      command_line.HasSwitch(switches::kAllowFileAccessFromFiles);
   }
 
   web_prefs.uses_universal_detector =
       prefs->GetBoolean(prefs::kWebKitUsesUniversalDetector);
   web_prefs.text_areas_are_resizable =
       prefs->GetBoolean(prefs::kWebKitTextAreasAreResizable);
 
   // User CSS is currently disabled because it crashes chrome.  See
   // webkit/glue/webpreferences.h for more details.
 
   // Make sure we will set the default_encoding with canonical encoding name.
   web_prefs.default_encoding =
       CharacterEncoding::GetCanonicalEncodingNameByAliasName(
           web_prefs.default_encoding);
   if (web_prefs.default_encoding.empty()) {
     prefs->ClearPref(prefs::kDefaultCharset);
     web_prefs.default_encoding = WideToASCII(
         prefs->GetString(prefs::kDefaultCharset));
   }
   DCHECK(!web_prefs.default_encoding.empty());
 
   if (is_dom_ui) {
     web_prefs.loads_images_automatically = true;
     web_prefs.javascript_enabled = true;
   }
 
   return web_prefs;
 }