CrOS GMC: add pin button to media controls dialog.

This CL adds a pin button in media tray dialog and media controls
detailed view. The button allows user to pin/unpin global media controls
to/from shelf. Global media controls will be pinned by default if the
primary display size is larger than 10 inches.

Bug: 1130963
Change-Id: I9eb8d8abbef7029141967fff43c17d2144287f82
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2422867
Commit-Queue: Jazz Xu <[email protected]>
Reviewed-by: Tim Song <[email protected]>
Reviewed-by: Xiyuan Xia <[email protected]>
Reviewed-by: Evan Stade <[email protected]>
Cr-Commit-Position: refs/heads/master@{#810391}
diff --git a/ash/ash_prefs.cc b/ash/ash_prefs.cc
index 6d86821..f4c1241d 100644
--- a/ash/ash_prefs.cc
+++ b/ash/ash_prefs.cc
@@ -24,6 +24,7 @@
 #include "ash/system/bluetooth/bluetooth_power_controller.h"
 #include "ash/system/caps_lock_notification_controller.h"
 #include "ash/system/gesture_education/gesture_education_notification_controller.h"
+#include "ash/system/media/media_tray.h"
 #include "ash/system/message_center/message_center_controller.h"
 #include "ash/system/network/vpn_list_view.h"
 #include "ash/system/night_light/night_light_controller_impl.h"
@@ -72,6 +73,7 @@
   TouchDevicesController::RegisterProfilePrefs(registry, for_test);
   tray::VPNListView::RegisterProfilePrefs(registry);
   WmGestureHandler::RegisterProfilePrefs(registry);
+  MediaTray::RegisterProfilePrefs(registry);
 
   // Provide prefs registered in the browser for ash_unittests.
   if (for_test) {