Tablet-like power button behavior on Convertible/Tablet ChromeOS devices

ash/BUILD.gn

Index: ash/BUILD.gn
diff --git a/ash/BUILD.gn b/ash/BUILD.gn
index ebd98b3efaad30f0b6a0b7bb5cbc2e0a25c27e0d..97f77e3103077186fb122bba9db3380dfcfa8f07 100644
--- a/ash/BUILD.gn
+++ b/ash/BUILD.gn
@@ -824,6 +824,8 @@ component("ash") {
     "wm/system_modal_container_event_filter_delegate.h",
     "wm/system_wallpaper_controller.cc",
     "wm/system_wallpaper_controller.h",
+    "wm/tablet_power_button_controller.cc",
+    "wm/tablet_power_button_controller.h",
     "wm/toplevel_window_event_handler.cc",
     "wm/toplevel_window_event_handler.h",
     "wm/video_detector.cc",
@@ -1340,6 +1342,7 @@ test("ash_unittests") {
     "wm/stacking_controller_unittest.cc",
     "wm/system_gesture_event_filter_unittest.cc",
     "wm/system_modal_container_layout_manager_unittest.cc",
+    "wm/tablet_power_button_controller_unittest.cc",
     "wm/toplevel_window_event_handler_unittest.cc",
     "wm/video_detector_unittest.cc",
     "wm/window_animations_unittest.cc",
@@ -1460,6 +1463,7 @@ test("ash_unittests") {
 
       # Talks to ChromeOS system services.
       "wm/lock_state_controller_unittest.cc",
+      "wm/tablet_power_button_controller_unittest.cc",
 
       # Maximize mode is only available on Chrome OS.
       "wm/maximize_mode/maximize_mode_controller_unittest.cc",