Add ability to change default pref values, and use in BrowserInstantController.

chrome/browser/profiles/profile_impl.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 "chrome/browser/profiles/profile_impl.h"
 
 #include "base/bind.h"
 #include "base/callback.h"
 #include "base/command_line.h"
 #include "base/compiler_specific.h"
@@ skipping 370 matching lines @@
   policy_service_ =
       g_browser_process->browser_policy_connector()->CreatePolicyService(this);
 #else
   policy_service_.reset(new policy::PolicyServiceStub());
 #endif
 
   DCHECK(create_mode == CREATE_MODE_ASYNCHRONOUS ||
          create_mode == CREATE_MODE_SYNCHRONOUS);
   bool async_prefs = create_mode == CREATE_MODE_ASYNCHRONOUS;
 
+  chrome::RegisterUserPrefs(pref_registry_);
+
   {
     // On startup, preference loading is always synchronous so a scoped timer
     // will work here.
     startup_metric_utils::ScopedSlowStartupUMA
         scoped_timer("Startup.SlowStartupPreferenceLoading");
     prefs_.reset(chrome_prefs::CreateProfilePrefs(
         GetPrefFilePath(),
         sequenced_task_runner,
         policy_service_.get(),
         new ExtensionPrefStore(
@@ skipping 299 matching lines @@
   return extension_special_storage_policy_.get();
 }
 
 void ProfileImpl::OnPrefsLoaded(bool success) {
   if (!success) {
     if (delegate_)
       delegate_->OnProfileCreated(this, false, false);
     return;
   }
 
-  // TODO(joi): Registration can move to the constructor once it
-  // doesn't need the PrefService parameter.
-  chrome::RegisterUserPrefs(prefs_.get(), pref_registry_);
-
   // TODO(mirandac): remove migration code after 6 months (crbug.com/69995).
   if (g_browser_process->local_state())
     chrome::MigrateBrowserPrefs(this, g_browser_process->local_state());
   // TODO(ivankr): remove cleanup code eventually (crbug.com/165672).
   chrome::MigrateUserPrefs(this);
 
   // |kSessionExitType| was added after |kSessionExitedCleanly|. If the pref
   // value is empty fallback to checking for |kSessionExitedCleanly|.
   const std::string exit_type_pref_value(
       prefs_->GetString(prefs::kSessionExitType));
@@ skipping 458 matching lines @@
                                      base::FilePath* cache_path,
                                      int* max_size) {
   DCHECK(cache_path);
   DCHECK(max_size);
   base::FilePath path(prefs_->GetFilePath(prefs::kDiskCacheDir));
   if (!path.empty())
     *cache_path = path;
   *max_size = is_media_context ? prefs_->GetInteger(prefs::kMediaCacheSize) :
                                  prefs_->GetInteger(prefs::kDiskCacheSize);
 }