mojo api for view based lockscreen

ash/login/ui/lock_contents_view.cc

Index: ash/login/ui/lock_contents_view.cc
diff --git a/ash/login/ui/lock_contents_view.cc b/ash/login/ui/lock_contents_view.cc
index c676efb97b06675117c0f5b336b1f2d337ff4d07..65342e56bb8a69b3af9612910d9714ef51dd88f5 100644
--- a/ash/login/ui/lock_contents_view.cc
+++ b/ash/login/ui/lock_contents_view.cc
@@ -4,6 +4,9 @@
 
 #include "ash/login/ui/lock_contents_view.h"
 
+#include "ash/login/lock_screen_controller.h"
+#include "ash/session/session_controller.h"
+#include "ash/shell.h"
 #include "base/strings/utf_string_conversions.h"
 #include "ui/views/background.h"
 #include "ui/views/border.h"
@@ -33,8 +36,15 @@ void LockContentsView::ButtonPressed(views::Button* sender,
                                      const ui::Event& event) {
   DCHECK(unlock_button_ == sender);
 
-  // TODO: Run mojo call that talks to backend which unlocks the device.
-  NOTIMPLEMENTED();
+  // TODO: user index shouldn't be hard coded here. Complete the implementation
+  // below.
+  const int kUserIndex = 0;

[James Cook, 2017/05/15 21:15:00]

super nit: When we're using a const local just to provide a nice name for a
variable, I prefer |user_index|.

[xiaoyinh(OOO Sep 11-29), 2017/05/16 17:32:50]

Done.

+  SessionController* session_controller = Shell::Get()->session_controller();
+  const mojom::UserSession* const user_session =
+      session_controller->GetUserSession(kUserIndex);

[James Cook, 2017/05/15 21:15:00]

nit: Just inline the call to Shell::Get()->session_controller() here since you
only use the pointer once.

[xiaoyinh(OOO Sep 11-29), 2017/05/16 17:32:50]

Done.

+  Shell::Get()->lock_screen_controller()->AuthenticateUser(
+      user_session->account_id, std::string(),
+      false /* authenticated_by_pin */);

[James Cook, 2017/05/15 21:15:00]

Thanks for documenting what false means here! It makes it easy for me to read.

 }
 
 }  // namespace ash