cros: Send NOTIFICATION_LOGIN_OR_LOCK_WEBUI_VISIBLE for views login/lock

It'd be better to remove the notification entirely, but there are still some
users of this notification, like accessibility and power. I suspect the correct
long-term fix is to migrate these users to session state changed observers.

Bug: 784495
Change-Id: I5a60f4ff4010cb11e541415bea11245766dd6eeb
Reviewed-on: https://chromium-review.googlesource.com/964713
Commit-Queue: Jacob Dufault <jdufault@chromium.org>
Reviewed-by: Xiyuan Xia <xiyuan@chromium.org>
Cr-Commit-Position: refs/heads/master@{#550698}

chrome/browser/chromeos/login/lock/screen_locker.cc

@@ -226,6 +226,11 @@ void ScreenLocker::Init() {
         [](ViewsScreenLocker* screen_locker, bool did_show) {
           CHECK(did_show);
           screen_locker->OnLockScreenReady();
+
+          content::NotificationService::current()->Notify(
+              chrome::NOTIFICATION_LOGIN_OR_LOCK_WEBUI_VISIBLE,
+              content::NotificationService::AllSources(),
+              content::NotificationService::NoDetails());
         },
         views_screen_locker_.get()));
 

chrome/browser/chromeos/login/ui/login_display_mojo.cc

@@ -4,6 +4,7 @@
 
 #include "chrome/browser/chromeos/login/ui/login_display_mojo.h"
 
+#include "chrome/browser/chrome_notification_types.h"
 #include "chrome/browser/chromeos/login/screens/chrome_user_selection_screen.h"
 #include "chrome/browser/chromeos/login/screens/user_selection_screen.h"
 #include "chrome/browser/chromeos/login/ui/login_display_host_mojo.h"
@@ -13,6 +14,7 @@
 #include "chromeos/dbus/dbus_thread_manager.h"
 #include "chromeos/dbus/session_manager_client.h"
 #include "components/user_manager/known_user.h"
+#include "content/public/browser/notification_service.h"
 
 namespace chromeos {
 
@@ -55,6 +57,11 @@ void LoginDisplayMojo::Init(const user_manager::UserList& filtered_users,
     chromeos::DBusThreadManager::Get()
         ->GetSessionManagerClient()
         ->EmitLoginPromptVisible();
+
+    content::NotificationService::current()->Notify(
+        chrome::NOTIFICATION_LOGIN_OR_LOCK_WEBUI_VISIBLE,
+        content::NotificationService::AllSources(),
+        content::NotificationService::NoDetails());
   }));
 
   user_selection_screen_->Init(filtered_users);