Make kCookiePromptExpanded a profile pref rather than a local state pref so it can be synced.

chrome/browser/sync/glue/synchronized_preferences.h

 // Copyright (c) 2010 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.
 
 // Defines a list of the preferences that the
 // PreferencesChangeProcessor should process changes for.
 
 #ifndef CHROME_BROWSER_SYNC_GLUE_SYNCHRONIZED_PREFERENCES_H_
 #define CHROME_BROWSER_SYNC_GLUE_SYNCHRONIZED_PREFERENCES_H_
 
@@ skipping 86 matching lines @@
   TranslatePrefs::kPrefTranslateLanguageBlacklist,
   TranslatePrefs::kPrefTranslateSiteBlacklist,
   TranslatePrefs::kPrefTranslateWhitelists,
   TranslatePrefs::kPrefTranslateDeniedCount,
   TranslatePrefs::kPrefTranslateAcceptedCount,
 
   // Desktop notification permissions.
   prefs::kDesktopNotificationAllowedOrigins,
   prefs::kDesktopNotificationDeniedOrigins,
 
+  // Cookie prompt dialog.
+  prefs::kCookiePromptExpanded,
+
 #if defined(OS_CHROMEOS)
   // IME prefs
   prefs::kLanguageHangulKeyboard,
   prefs::kLanguagePinyinAutoCommit,
   prefs::kLanguagePinyinCommaPeriodPage,
   prefs::kLanguagePinyinCorrectPinyin,
   prefs::kLanguagePinyinDoublePinyin,
   prefs::kLanguagePinyinFuzzyPinyin,
   prefs::kLanguagePinyinInitChinese,
   prefs::kLanguagePinyinInitFull,
@@ skipping 30 matching lines @@
   //   prefs::kLanguagePinyinDoublePinyinSchema,
   //   prefs::kLanguagePinyinLookupTablePageSize,
   //
   // We don't sync prefs::kLanguageCurrentInputMethod and PreviousInputMethod.
 #endif
 };
 
 }  // namespace browser_sync
 
 #endif  // CHROME_BROWSER_SYNC_GLUE_SYNCHRONIZED_PREFERENCES_H_