Make LockScreenActionTray item visible only with show-md-login flag

The entry point for note taking on lock screen has been added to the
lock screen UI for webui lock screen implementation - this means that
the item in the system tray is not longer needed in this case.

Keep the tray item around for views based lock screen (i.e.
when show-md-login flag is set) - in this case the lock screen UI
has yet to be updated, so there is still a need for an entry point in
the tray.

BUG=737067

Change-Id: I53c53c7154c1dfec165c6a9898359b29b366db3f
Reviewed-on: https://chromium-review.googlesource.com/578647
Commit-Queue: Toni Barzic <tbarzic@chromium.org>
Reviewed-by: Terry Anderson <tdanderson@chromium.org>
Cr-Commit-Position: refs/heads/master@{#488355}

ash/system/lock_screen_action/lock_screen_action_tray.cc

@@ -12,7 +12,9 @@
 #include "ash/system/tray/tray_constants.h"
 #include "ash/system/tray/tray_container.h"
 #include "ash/tray_action/tray_action.h"
+#include "base/command_line.h"
 #include "base/logging.h"
+#include "chromeos/chromeos_switches.h"
 #include "ui/base/l10n/l10n_util.h"
 #include "ui/gfx/geometry/size.h"
 #include "ui/gfx/paint_vector_icon.h"
@@ -21,12 +23,33 @@
 
 namespace ash {
 
+namespace {
+
+bool IsLockScreenActionTrayEnabled() {
+  // The lock screen action entry point will be move from system tray to the
+  // lock screen UI - for current incarnation of lock screen UI, this has
+  // already been done, so the tray action button is not needed in this case.
+  // For views base lock screen (used when show-md-login is set), this is not
+  // the case.
+  // TODO(tbarzic): Replace LockScreenActionTray item with a button in the lock
+  //     screen UI for views base lock screen implementation.
+  //     http://crbug.com/746596
+  return base::CommandLine::ForCurrentProcess()->HasSwitch(
+      chromeos::switches::kShowMdLogin);
+}
+
+}  // namespace
+
 LockScreenActionTray::LockScreenActionTray(Shelf* shelf)
     : TrayBackgroundView(shelf),
       session_observer_(this),
       tray_action_observer_(this) {
-  SetInkDropMode(InkDropMode::ON);
   SetVisible(false);
+
+  if (!IsLockScreenActionTrayEnabled())
+    return;
+
+  SetInkDropMode(InkDropMode::ON);
   new_note_action_view_ = new views::ImageView();
   new_note_action_view_->SetImage(
       CreateVectorIcon(kTrayActionNewLockScreenNoteIcon, kShelfIconColor));
@@ -42,6 +65,9 @@ LockScreenActionTray::~LockScreenActionTray() {}
 void LockScreenActionTray::Initialize() {
   TrayBackgroundView::Initialize();
 
+  if (!IsLockScreenActionTrayEnabled())
+    return;
+
   session_observer_.Add(Shell::Get()->session_controller());
 
   TrayAction* controller = Shell::Get()->tray_action();
@@ -80,7 +106,8 @@ void LockScreenActionTray::OnLockScreenNoteStateChanged(
 }
 
 bool LockScreenActionTray::IsStateVisible() const {
-  return Shell::Get()->session_controller()->IsScreenLocked() &&
+  return IsLockScreenActionTrayEnabled() &&
+         Shell::Get()->session_controller()->IsScreenLocked() &&
          (new_note_state_ == mojom::TrayActionState::kAvailable ||
           new_note_state_ == mojom::TrayActionState::kLaunching);
 }

ash/system/lock_screen_action/lock_screen_action_tray_unittest.cc

@@ -12,7 +12,9 @@
 #include "ash/system/status_area_widget_test_helper.h"
 #include "ash/test/ash_test_base.h"
 #include "ash/tray_action/tray_action.h"
+#include "base/command_line.h"
 #include "base/macros.h"
+#include "chromeos/chromeos_switches.h"
 #include "components/session_manager/session_manager_types.h"
 #include "ui/events/test/event_generator.h"
 #include "ui/gfx/image/image_skia.h"
@@ -58,6 +60,12 @@ class LockScreenActionTrayTest : public AshTestBase {
   LockScreenActionTrayTest() = default;
   ~LockScreenActionTrayTest() override = default;
 
+  void SetUp() override {
+    base::CommandLine::ForCurrentProcess()->AppendSwitch(
+        chromeos::switches::kShowMdLogin);
+    AshTestBase::SetUp();
+  }
+
   void ClickOnTray() {
     // Perform click on the tray view.
     ui::test::EventGenerator& generator = GetEventGenerator();
@@ -72,6 +80,8 @@ class LockScreenActionTrayTest : public AshTestBase {
   DISALLOW_COPY_AND_ASSIGN(LockScreenActionTrayTest);
 };
 
+using LockScreenActionTrayWithoutMdLoginTest = AshTestBase;
+
 }  // namespace
 
 TEST_F(LockScreenActionTrayTest, NoClient) {
@@ -229,4 +239,27 @@ TEST_F(LockScreenActionTrayTest, TrayNotVisibleWhenSessionNotLocked) {
   EXPECT_FALSE(GetTray()->visible());
 }
 
+TEST_F(LockScreenActionTrayWithoutMdLoginTest, NotVisible) {
+  SetUserLoggedIn(true);
+
+  TrayAction* tray_action = Shell::Get()->tray_action();
+  TestTrayActionClient tray_action_client;
+  tray_action->SetClient(tray_action_client.CreateInterfacePtrAndBind(),
+                         mojom::TrayActionState::kNotAvailable);
+
+  EXPECT_FALSE(GetTray()->visible());
+
+  tray_action->UpdateLockScreenNoteState(mojom::TrayActionState::kAvailable);
+  EXPECT_FALSE(GetTray()->visible());
+
+  tray_action->UpdateLockScreenNoteState(mojom::TrayActionState::kLaunching);
+  EXPECT_FALSE(GetTray()->visible());
+
+  tray_action->UpdateLockScreenNoteState(mojom::TrayActionState::kActive);
+  EXPECT_FALSE(GetTray()->visible());
+
+  tray_action->UpdateLockScreenNoteState(mojom::TrayActionState::kBackground);
+  EXPECT_FALSE(GetTray()->visible());
+}
+
 }  // namespace ash