Allow passing in a file path to a file that will be used for the new new tab...

chrome/common/chrome_switches.cc

 // Copyright (c) 2006-2009 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/common/chrome_switches.h"
 
 #include "base/base_switches.h"
 
 namespace switches {
 
@@ skipping 452 matching lines @@
 // parsed by the renderer, and consists of a field test name, and a forced
 // selection of an outcome.  For example, if a field test "DnsImpact" has
 // selected "_disabled_prefetch" as a current test, then the render should be
 // passed the command line:
 //      force-fieldtest=DnsImpact/_disabled_prefetch
 // The renderer will then force said named field test to exist, and will force
 // the selected outcome to have the indicated text value.
 const wchar_t kForceFieldTestNameAndValue[]    = L"force-fieldtest";
 
 // Enables the prototype of the next version of the New Tab page.
+// This can be empty in which case the default prototype resource is used or it
+// can be a file path, in which case the file will be used as the new tab page.
 const wchar_t kNewNewTabPage[]                 = L"new-new-tab-page";
 
 }  // namespace switches