Introduce //components/user_prefs, use to eliminate c/b/prefs dependency in Autofill.

chrome/browser/profiles/profile.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.h"
 
 #include <string>
 
 #include "base/prefs/pref_service.h"
 #include "build/build_config.h"
-#include "chrome/browser/prefs/pref_registry_syncable.h"
 #include "chrome/browser/sync/profile_sync_service.h"
 #include "chrome/browser/sync/sync_prefs.h"
 #include "chrome/common/chrome_notification_types.h"
 #include "chrome/common/pref_names.h"
+#include "components/user_prefs/pref_registry_syncable.h"
+#include "components/user_prefs/user_prefs.h"
+#include "components/user_prefs/user_prefs_delegate.h"
 #include "content/public/browser/notification_service.h"
 #include "content/public/browser/notification_source.h"
 #include "content/public/browser/web_contents.h"
 #include "content/public/browser/web_ui.h"
 
 #if defined(OS_CHROMEOS)
 #include "base/command_line.h"
 #include "chrome/common/chrome_switches.h"
 #endif
 
+namespace {
+
+// Used to initialize the UserPrefs component.
+class ChromeUserPrefsDelegate : public components::UserPrefsDelegate {
+ public:
+  ChromeUserPrefsDelegate() {}
+  virtual ~ChromeUserPrefsDelegate() {}
+
+  virtual PrefService* PrefServiceFromBrowserContext(
+      content::BrowserContext* context) OVERRIDE {
+    return static_cast<Profile*>(context)->GetPrefs();
+  }
+
+ private:
+  DISALLOW_COPY_AND_ASSIGN(ChromeUserPrefsDelegate);
+};
+
+}  // namespace
+
 Profile::Profile()
     : restored_last_session_(false),
       sent_destroyed_notification_(false),
       accessibility_pause_level_(0) {
+  // One-time initialization of UserPrefs. This is the safest to do
+  // it, since there can be no PrefService for user preferences unless
+  // there is a Profile, and even test code will create a Profile
+  // object if it uses a Profile at all, although it may bypass
+  // e.g. BrowserProcess or ProfileManager or
+  // chrome_prefs::CreateProfilePrefs.
+  components::UserPrefs* user_prefs = components::UserPrefs::GetInstance();

[Elliot Glaysher, 2013/02/28 21:58:57]

You mentioned ContetnClient. If this is supposed to be a single, global
singleton, putting this in the startup code (ChromeMainDelegate or one of its
ExtraParts) would make more sense.

Putting it here doesn't make it feel like this is startup code, but something
user configurable since Profile isn't the only consumer of BrowserContexts.

+  if (!user_prefs->IsInitialized()) {
+    user_prefs->Initialize(scoped_ptr<components::UserPrefsDelegate>(
+        new ChromeUserPrefsDelegate).Pass());
+  }
 }
 
 // static
 Profile* Profile::FromBrowserContext(content::BrowserContext* browser_context) {
   // This is safe; this is the only implementation of the browser context.
   return static_cast<Profile*>(browser_context);
 }
 
 // static
 Profile* Profile::FromWebUI(content::WebUI* web_ui) {
@@ skipping 96 matching lines @@
 
 void Profile::MaybeSendDestroyedNotification() {
   if (!sent_destroyed_notification_) {
     sent_destroyed_notification_ = true;
     content::NotificationService::current()->Notify(
         chrome::NOTIFICATION_PROFILE_DESTROYED,
         content::Source<Profile>(this),
         content::NotificationService::NoDetails());
   }
 }