Implemented a policy for centralized setting of the --disk-cache-dir flag.

chrome/browser/browser_process_impl.cc

 // Copyright (c) 2011 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/browser_process_impl.h"
 
 #include <map>
 #include <set>
 #include <vector>
 
@@ skipping 888 matching lines @@
   }
   pref_change_registrar_.Add(prefs::kDefaultBrowserSettingEnabled, this);
 
   // Initialize the preference for the plugin finder policy.
   // This preference is only needed on the IO thread so make it available there.
   local_state_->RegisterBooleanPref(prefs::kDisablePluginFinder, false);
   plugin_finder_disabled_pref_.Init(prefs::kDisablePluginFinder,
                                    local_state_.get(), NULL);
   plugin_finder_disabled_pref_.MoveToThread(BrowserThread::IO);
 
+  // Initialize the disk cache location policy. This policy is not hot update-
+  // able so we need to have it when initializing the profiles.
+  local_state_->RegisterFilePathPref(prefs::kDiskCacheDir, FilePath());
+
   // This is observed by ChildProcessSecurityPolicy, which lives in content/
   // though, so it can't register itself.
   local_state_->RegisterListPref(prefs::kDisabledSchemes);
   pref_change_registrar_.Add(prefs::kDisabledSchemes, this);
   ApplyDisabledSchemesPolicy();
 }
 
 void BrowserProcessImpl::CreateIconManager() {
   DCHECK(!created_icon_manager_ && icon_manager_.get() == NULL);
   created_icon_manager_ = true;
@@ skipping 187 matching lines @@
 }
 
 void BrowserProcessImpl::OnAutoupdateTimer() {
   if (CanAutorestartForUpdate()) {
     DLOG(WARNING) << "Detected update.  Restarting browser.";
     RestartPersistentInstance();
   }
 }
 
 #endif  // (defined(OS_WIN) || defined(OS_LINUX)) && !defined(OS_CHROMEOS)