Refuse to start if we can't get the user data directory.

chrome/common/chrome_paths.cc

 // Copyright (c) 2006-2008 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_paths.h"
 
 #include "base/command_line.h"
 #include "base/file_path.h"
 #include "base/file_util.h"
 #include "base/logging.h"
@@ skipping 56 matching lines @@
       return PathService::Get(base::FILE_MODULE, result);
   }
 
   // Assume that we will not need to create the directory if it does not exist.
   // This flag can be set to true for the cases where we want to create it.
   bool create_dir = false;
 
   FilePath cur;
   switch (key) {
     case chrome::DIR_USER_DATA:
-      if (!GetDefaultUserDataDirectory(&cur))
+      if (!GetDefaultUserDataDirectory(&cur)) {
+        NOTREACHED();
         return false;
+      }
       create_dir = true;
       break;
     case chrome::DIR_USER_CACHE:
 #if defined(OS_LINUX)
       if (!GetUserCacheDirectory(&cur))
         return false;
       create_dir = true;
 #else
       // No concept of a separate cache directory on non-Linux systems.
       return false;
@@ skipping 124 matching lines @@
   return true;
 }
 
 // This cannot be done as a static initializer sadly since Visual Studio will
 // eliminate this object file if there is no direct entry point into it.
 void RegisterPathProvider() {
   PathService::RegisterProvider(PathProvider, PATH_START, PATH_END);
 }
 
 }  // namespace chrome