Add a couple of notifications related settings to app/extensions sync:

chrome/browser/extensions/extension_prefs.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/extensions/extension_prefs.h"
 
 #include "base/string_number_conversions.h"
 #include "base/string_util.h"
 #include "base/utf_string_conversions.h"
 #include "chrome/browser/extensions/extension_pref_store.h"
@@ skipping 27 matching lines @@
 
 // The dictionary containing the extension's manifest.
 const char kPrefManifest[] = "manifest";
 
 // The version number.
 const char kPrefVersion[] = "manifest.version";
 
 // Indicates whether an extension is blacklisted.
 const char kPrefBlacklist[] = "blacklist";
 
+// Indicates whether the user has done app notifications setup or not.
+const char kPrefAppNotificationSetup[] = "app_notif_setup";
+
+// Indicates whether the user has disabled notifications or not.
+const char kPrefAppNotificationDisbaled[] = "app_notif_disabled";
+
 // Indicates whether the user has acknowledged various types of extensions.
 const char kPrefExternalAcknowledged[] = "ack_external";
 const char kPrefBlacklistAcknowledged[] = "ack_blacklist";
 const char kPrefOrphanAcknowledged[] = "ack_orphan";
 
 // Indicates whether to show an install warning when the user enables.
 const char kExtensionDidEscalatePermissions[] = "install_warning_on_enable";
 
 // A preference that tracks browser action toolbar configuration. This is a list
 // object stored in the Preferences file. The extensions are stored by ID.
@@ skipping 302 matching lines @@
 
 // static
 bool ExtensionPrefs::ReadBooleanFromPref(
     const DictionaryValue* ext, const std::string& pref_key) {
   bool bool_value = false;
   ext->GetBoolean(pref_key, &bool_value);
   return bool_value;
 }
 
 bool ExtensionPrefs::ReadExtensionPrefBoolean(
-    const std::string& extension_id, const std::string& pref_key) {
+    const std::string& extension_id, const std::string& pref_key) const {
   const DictionaryValue* ext = GetExtensionPref(extension_id);
   if (!ext) {
     // No such extension yet.
     return false;
   }
   return ReadBooleanFromPref(ext, pref_key);
 }
 
 // static
 bool ExtensionPrefs::ReadIntegerFromPref(
@@ skipping 198 matching lines @@
 }
 
 bool ExtensionPrefs::SetAlertSystemFirstRun() {
   if (prefs_->GetBoolean(prefs::kExtensionAlertsInitializedPref)) {
     return true;
   }
   prefs_->SetBoolean(prefs::kExtensionAlertsInitializedPref, true);
   return false;
 }
 
+bool ExtensionPrefs::IsAppNotificationSetupDone(
+    const std::string& extension_id) const {
+  return ReadExtensionPrefBoolean(
+      extension_id, kPrefAppNotificationSetup);
+}
+
+void ExtensionPrefs::SetAppNotificationSetupDone(
+    const std::string& extension_id,
+    bool value) {
+  DCHECK(Extension::IdIsValid(extension_id));

[asargent_no_longer_on_chrome, 2011/10/27 19:49:41]

nit: UpdateExtensionPref already checks IdIsValid, so you can skip this here

+  UpdateExtensionPref(extension_id, kPrefAppNotificationSetup,
+                      Value::CreateBooleanValue(value));
+}
+
+bool ExtensionPrefs::IsAppNotificationDisabled(
+    const std::string& extension_id) const {
+  return ReadExtensionPrefBoolean(extension_id, kPrefAppNotificationDisbaled);
+}
+
+void ExtensionPrefs::SetAppNotificationDisabled(
+   const std::string& extension_id, bool value) {
+  DCHECK(Extension::IdIsValid(extension_id));

[asargent_no_longer_on_chrome, 2011/10/27 19:49:41]

nit: UpdateExtensionPref already checks IdIsValid, so you can skip this here

+  UpdateExtensionPref(extension_id, kPrefAppNotificationDisbaled,
+                      Value::CreateBooleanValue(value));
+}
+
 bool ExtensionPrefs::IsExtensionAllowedByPolicy(
     const std::string& extension_id) {
   std::string string_value;
 
   const ListValue* blacklist =
       prefs_->GetList(prefs::kExtensionInstallDenyList);
   if (!blacklist || blacklist->empty())
     return true;
 
   // Check the whitelist first.
@@ skipping 1193 matching lines @@
   prefs->RegisterListPref(prefs::kExtensionInstallAllowList,
                           PrefService::UNSYNCABLE_PREF);
   prefs->RegisterListPref(prefs::kExtensionInstallDenyList,
                           PrefService::UNSYNCABLE_PREF);
   prefs->RegisterListPref(prefs::kExtensionInstallForceList,
                           PrefService::UNSYNCABLE_PREF);
   prefs->RegisterStringPref(kWebStoreLogin,
                             std::string() /* default_value */,
                             PrefService::UNSYNCABLE_PREF);
 }