Fix chromium-os:10777 and other sync related crashes.

chrome/browser/profiles/profile_impl.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/profiles/profile_impl.h"
 
 #include "app/resource_bundle.h"
 #include "base/command_line.h"
 #include "base/environment.h"
 #include "base/file_path.h"
@@ skipping 1230 matching lines @@
 
 TokenService* ProfileImpl::GetTokenService() {
   if (!token_service_.get()) {
     token_service_.reset(new TokenService());
   }
   return token_service_.get();
 }
 
 ProfileSyncService* ProfileImpl::GetProfileSyncService() {
 #if defined(OS_CHROMEOS)
-  // If kLoginManager is specified, we shouldn't call this unless login has
-  // completed and specified cros_user. Guard with if (HasProfileSyncService())
-  // where this might legitimately get called before login has completed.
-  if (!sync_service_.get() &&
-      CommandLine::ForCurrentProcess()->HasSwitch(switches::kLoginManager)) {
-    LOG(FATAL) << "GetProfileSyncService() called before login complete.";
+  if (!sync_service_.get()) {
+    // In ChromeOS, sync only gets initialized properly from login, when
+    // kLoginManager is specified. If this gets called before login, or
+    // during a debugging session without kLoginManager, this will return
+    // NULL, so ensure that calls either handle a NULL result, or use
+    // HasProfileSyncService() to guard against the call.
+    return NULL;
   }
 #endif
   return GetProfileSyncService("");
 }
 
 ProfileSyncService* ProfileImpl::GetProfileSyncService(
     const std::string& cros_user) {
 
   if (!ProfileSyncService::IsSyncEnabled())
     return NULL;
@@ skipping 97 matching lines @@
 }
 
 PrerenderManager* ProfileImpl::GetPrerenderManager() {
   CommandLine* cl = CommandLine::ForCurrentProcess();
   if (!cl->HasSwitch(switches::kEnablePagePrerender))
     return NULL;
   if (!prerender_manager_)
     prerender_manager_ = new PrerenderManager(this);
   return prerender_manager_;
 }