Don't sync browser.show_home_button and homepage_is_newtabpage to mobile platforms.

chrome/browser/ui/browser_ui_prefs.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/ui/browser_ui_prefs.h"
 
 #include "build/build_config.h"
 #include "chrome/browser/first_run/first_run.h"
 #include "chrome/browser/profiles/profile.h"
 #include "chrome/common/pref_names.h"
 #include "components/pref_registry/pref_registry_syncable.h"
 #include "components/prefs/pref_registry_simple.h"
 #include "components/prefs/pref_service.h"
 #include "components/prefs/scoped_user_pref_update.h"
 #include "components/translate/core/common/translate_pref_names.h"
 #include "content/public/common/webrtc_ip_handling_policy.h"
 
 #if defined(OS_WIN)
 #include "base/win/windows_version.h"
 #endif
 
+namespace {
+
+uint32_t GetHomeButtonAndHomePageIsNewTabPageFlags() {
+#if defined(OS_IOS) || defined(OS_ANDROID)
+  return PrefRegistry::NO_REGISTRATION_FLAGS;
+#else
+  return user_prefs::PrefRegistrySyncable::SYNCABLE_PREF;
+#endif
+}
+
+}  // namespace
+
 namespace chrome {
 
 void RegisterBrowserPrefs(PrefRegistrySimple* registry) {
   registry->RegisterIntegerPref(prefs::kOptionsWindowLastTabIndex, 0);
   registry->RegisterBooleanPref(prefs::kAllowFileSelectionDialogs, true);
   registry->RegisterIntegerPref(prefs::kShowFirstRunBubbleOption,
                              first_run::FIRST_RUN_BUBBLE_DONT_SHOW);
 }
 
 void RegisterBrowserUserPrefs(user_prefs::PrefRegistrySyncable* registry) {
   registry->RegisterBooleanPref(
       prefs::kHomePageIsNewTabPage,
       true,
-      user_prefs::PrefRegistrySyncable::SYNCABLE_PREF);
-  registry->RegisterBooleanPref(
-      prefs::kShowHomeButton,
-      false,
-      user_prefs::PrefRegistrySyncable::SYNCABLE_PREF);
+      GetHomeButtonAndHomePageIsNewTabPageFlags());
+  registry->RegisterBooleanPref(prefs::kShowHomeButton, false,
+                                GetHomeButtonAndHomePageIsNewTabPageFlags());
   registry->RegisterBooleanPref(
       prefs::kDeleteBrowsingHistory,
       true,
       user_prefs::PrefRegistrySyncable::SYNCABLE_PREF);
   registry->RegisterBooleanPref(
       prefs::kDeleteDownloadHistory,
       true,
       user_prefs::PrefRegistrySyncable::SYNCABLE_PREF);
   registry->RegisterBooleanPref(
       prefs::kDeleteCache,
@@ skipping 93 matching lines @@
   registry->RegisterBooleanPref(
       prefs::kHideFullscreenToolbar,
       false,
       user_prefs::PrefRegistrySyncable::SYNCABLE_PREF);
 #else
   registry->RegisterBooleanPref(prefs::kFullscreenAllowed, true);
 #endif
 }
 
 }  // namespace chrome