Fix a crash seen at times when chrome in desktop mode attempts to activate Chrome in Windows 8 mode…

win8/metro_driver/chrome_url_launch_handler.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 "stdafx.h"
 #include "chrome_url_launch_handler.h"
 #include "chrome_app_view.h"
 
 #include <assert.h>
 #include <shellapi.h>
@@ skipping 84 matching lines @@
   // navigation. In all other cases navigate right away.
   if (!globals.is_initial_activation)
     InitiateNavigationOrSearchRequest(globals.navigation_url.c_str(), 0);
 }
 
 // |launch_args| is an encoded command line, minus the executable name. To
 // find the URL to launch the first argument is used. If any other parameters
 // are encoded in |launch_args| they are ignored.
 string16 ChromeUrlLaunchHandler::GetUrlFromLaunchArgs(
     const string16& launch_args) {
+  if (launch_args == L"opennewwindow") {
+    VLOG(1) << "Returning new tab url";
+    return L"chrome://newtab";
+  }
   string16 dummy_command_line(L"dummy.exe ");
   dummy_command_line.append(launch_args);
   CommandLine command_line = CommandLine::FromString(dummy_command_line);
   CommandLine::StringVector args = command_line.GetArgs();
   if (args.size() > 0)
     return args[0];
 
   return string16();
 }
 
@@ skipping 57 matching lines @@
     const wchar_t* url, const wchar_t* search_string) {
   DVLOG(1) << __FUNCTION__;
   if (!url && !search_string) {
     NOTREACHED();
     return;
   }
 
   DVLOG(1) << (url ? url : L"NULL url");
   DVLOG(1) << (search_string ? search_string : L"NULL search string");
 
+  if (globals.host_windows.empty()) {
+    DVLOG(1) << "No chrome windows registered. Ignoring nav request";
+    return;
+  }
+
   // Custom registered message to navigate or search in chrome. WPARAM
   // points to the URL and LPARAM contains the search string. They are
   // mutually exclusive.
   static const UINT navigation_search_message =
       RegisterWindowMessage(kMetroNavigationAndSearchMessage);
 
   if (url) {
     VLOG(1) << "Posting url:" << url;
     PostMessage(globals.host_windows.front().first, navigation_search_message,
                 reinterpret_cast<WPARAM>(url), 0);
   } else {
     VLOG(1) << "Posting search string:" << search_string;
     PostMessage(globals.host_windows.front().first, navigation_search_message,
                 0, reinterpret_cast<LPARAM>(search_string));
   }
 }