cros: Fix easy unlock app causing crash on login screen.

EasyUnlockService is created with profile. Previous code to prevent
it from being created on login screen does not work for all cases.
Move the logic to EasyUnlockServiceFactory::GetBrowserContextToUse
fixes the issue.

BUG=399705
TBR=rogerta@chromium.org

Review URL: https://codereview.chromium.org/423363004

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@287176 0039d316-1c4b-4281-b951-d872f2087c98

chrome/browser/signin/easy_unlock_service_factory.cc

@@ -23,10 +23,6 @@ EasyUnlockServiceFactory* EasyUnlockServiceFactory::GetInstance() {
 
 // static
 EasyUnlockService* EasyUnlockServiceFactory::GetForProfile(Profile* profile) {
-#if defined(OS_CHROMEOS)
-  if (chromeos::ProfileHelper::IsSigninProfile(profile))
-    return NULL;
-#endif
   return static_cast<EasyUnlockService*>(
       EasyUnlockServiceFactory::GetInstance()->GetServiceForBrowserContext(
           profile, true));
@@ -50,6 +46,12 @@ KeyedService* EasyUnlockServiceFactory::BuildServiceInstanceFor(
 
 content::BrowserContext* EasyUnlockServiceFactory::GetBrowserContextToUse(
       content::BrowserContext* context) const {
+#if defined(OS_CHROMEOS)
+  if (chromeos::ProfileHelper::IsSigninProfile(
+          Profile::FromBrowserContext(context))) {
+    return NULL;
+  }
+#endif
   return chrome::GetBrowserContextRedirectedInIncognito(context);
 }