Use correct theme for the off icon of NightLight, fix tooltip and a11y

ash/system/tiles/tiles_default_view.cc

Index: ash/system/tiles/tiles_default_view.cc
diff --git a/ash/system/tiles/tiles_default_view.cc b/ash/system/tiles/tiles_default_view.cc
index b67d34e8f7c7892197edd54d860fa00eb9eb8a08..9487a21653612b05a7c76af3da225f2e0b1cd144 100644
--- a/ash/system/tiles/tiles_default_view.cc
+++ b/ash/system/tiles/tiles_default_view.cc
@@ -17,12 +17,15 @@
 #include "ash/system/tray/system_tray_controller.h"
 #include "ash/system/tray/system_tray_item.h"
 #include "ash/system/tray/tray_constants.h"
+#include "ash/system/tray/tray_popup_item_style.h"
 #include "ash/system/tray/tray_popup_utils.h"
 #include "ash/wm/lock_state_controller.h"
 #include "chromeos/dbus/dbus_thread_manager.h"
 #include "chromeos/dbus/session_manager_client.h"
+#include "ui/accessibility/ax_node_data.h"
 #include "ui/base/l10n/l10n_util.h"
 #include "ui/gfx/geometry/insets.h"
+#include "ui/gfx/paint_vector_icon.h"
 #include "ui/views/border.h"
 #include "ui/views/controls/button/custom_button.h"
 #include "ui/views/controls/separator.h"
@@ -36,14 +39,62 @@ namespace {
 // not mirrored in this locale.
 const char kHebrewLocale[] = "he";
 
-const gfx::VectorIcon& GetNightLightButtonIcon() {
-  return Shell::Get()->night_light_controller()->GetEnabled()
-             ? kSystemMenuNightLightOnIcon
-             : kSystemMenuNightLightOffIcon;
+gfx::ImageSkia GetNightLightNormalStateIcon(bool night_light_enabled) {
+  if (night_light_enabled)
+    return gfx::CreateVectorIcon(kSystemMenuNightLightOnIcon, kMenuIconColor);
+
+  // Use the same icon theme used for inactive items in the tray when
+  // NightLight is not active.
+  return gfx::CreateVectorIcon(kSystemMenuNightLightOffIcon,
+                               TrayPopupItemStyle::GetIconColor(
+                                   TrayPopupItemStyle::ColorStyle::INACTIVE));
+}
+
+gfx::ImageSkia GetNightLightDisabledStateIcon(bool night_light_enabled) {
+  return gfx::CreateVectorIcon(night_light_enabled
+                                   ? kSystemMenuNightLightOnIcon
+                                   : kSystemMenuNightLightOffIcon,
+                               kMenuIconColorDisabled);
 }
 
 }  // namespace
 
+// The NightLight toggle button in the system tray.
+class NightLightToggleButton : public SystemMenuButton {
+ public:
+  NightLightToggleButton(views::ButtonListener* listener)

[Daniel Erat, 2017/05/25 16:17:34]

explicit

[afakhry, 2017/05/25 16:31:38]

Done.
I remember the presubmit script used to catch this before. It seems it doesn't
now.

+      : SystemMenuButton(listener,
+                         TrayPopupInkDropStyle::HOST_CENTERED,
+                         kSystemMenuNightLightOffIcon,
+                         IDS_ASH_STATUS_TRAY_NIGHT_LIGHT) {
+    Update();
+  }
+  ~NightLightToggleButton() override = default;
+
+  // Updates the icon and its style based on the status of NightLight.
+  void Update() {
+    const bool night_light_enabled =
+        Shell::Get()->night_light_controller()->GetEnabled();
+
+    SetImage(views::Button::STATE_NORMAL,
+             GetNightLightNormalStateIcon(night_light_enabled));
+    SetImage(views::Button::STATE_DISABLED,
+             GetNightLightDisabledStateIcon(night_light_enabled));
+  }
+
+ private:
+  // views::View:
+  void GetAccessibleNodeData(ui::AXNodeData* node_data) override {
+    node_data->SetName(
+        l10n_util::GetStringUTF16(IDS_ASH_STATUS_TRAY_NIGHT_LIGHT));
+    node_data->role = ui::AX_ROLE_TOGGLE_BUTTON;
+    if (Shell::Get()->night_light_controller()->GetEnabled())
+      node_data->AddState(ui::AX_STATE_PRESSED);
+  }
+
+  DISALLOW_COPY_AND_ASSIGN(NightLightToggleButton);
+};
+
 TilesDefaultView::TilesDefaultView(SystemTrayItem* owner)
     : owner_(owner),
       settings_button_(nullptr),
@@ -91,9 +142,7 @@ void TilesDefaultView::Init() {
   AddChildView(help_button_);
   AddChildView(TrayPopupUtils::CreateVerticalSeparator());
 
-  night_light_button_ = new SystemMenuButton(
-      this, TrayPopupInkDropStyle::HOST_CENTERED, GetNightLightButtonIcon(),
-      IDS_ASH_STATUS_TRAY_NIGHT_LIGHT);
+  night_light_button_ = new NightLightToggleButton(this);
   night_light_button_->SetEnabled(can_show_web_ui);
   AddChildView(night_light_button_);
   AddChildView(TrayPopupUtils::CreateVerticalSeparator());
@@ -130,7 +179,7 @@ void TilesDefaultView::ButtonPressed(views::Button* sender,
   } else if (sender == night_light_button_) {
     ShellPort::Get()->RecordUserMetricsAction(UMA_TRAY_NIGHT_LIGHT);
     Shell::Get()->night_light_controller()->Toggle();
-    night_light_button_->SetVectorIcon(GetNightLightButtonIcon());
+    night_light_button_->Update();
   } else if (sender == lock_button_) {
     ShellPort::Get()->RecordUserMetricsAction(UMA_TRAY_LOCK_SCREEN);
     chromeos::DBusThreadManager::Get()