Don't sync homepage pref to mobile platforms.

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 <stddef.h>
 
 #include <memory>
 #include <utility>
@@ skipping 351 matching lines @@
   registry->RegisterBooleanPref(
       prefs::kProfileUsingDefaultName,
       true,
       user_prefs::PrefRegistrySyncable::SYNCABLE_PREF);
   registry->RegisterStringPref(prefs::kProfileName,
                                std::string(),
                                user_prefs::PrefRegistrySyncable::SYNCABLE_PREF);
 #endif
 
   registry->RegisterStringPref(prefs::kSupervisedUserId, std::string());
+#if defined(OS_IOS) || defined(OS_ANDROID)
+  uint32_t home_page_flags = PrefRegistry::NO_REGISTRATION_FLAGS;
+#else
+  uint32_t home_page_flags = user_prefs::PrefRegistrySyncable::SYNCABLE_PREF;
+#endif
   registry->RegisterStringPref(prefs::kHomePage,
                                std::string(),
-                               user_prefs::PrefRegistrySyncable::SYNCABLE_PREF);
+                               home_page_flags);
 #if defined(ENABLE_PRINTING)
   registry->RegisterBooleanPref(prefs::kPrintingEnabled, true);
 #endif
   registry->RegisterBooleanPref(prefs::kPrintPreviewDisabled, false);
   registry->RegisterStringPref(
       prefs::kPrintPreviewDefaultDestinationSelectionRules, std::string());
   registry->RegisterBooleanPref(prefs::kForceEphemeralProfiles, false);
 #if defined(ENABLE_MEDIA_ROUTER)
   registry->RegisterBooleanPref(prefs::kEnableMediaRouter, true);
 #endif
@@ skipping 892 matching lines @@
 ProfileImpl::CreateDomainReliabilityMonitor(PrefService* local_state) {
   domain_reliability::DomainReliabilityService* service =
       domain_reliability::DomainReliabilityServiceFactory::GetInstance()->
           GetForBrowserContext(this);
   if (!service)
     return std::unique_ptr<domain_reliability::DomainReliabilityMonitor>();
 
   return service->CreateMonitor(
       BrowserThread::GetMessageLoopProxyForThread(BrowserThread::IO));
 }