Mash: Show app icons in shelf based on the Widget's app icon

components/mus/public/interfaces/window_manager.mojom

Index: components/mus/public/interfaces/window_manager.mojom
diff --git a/components/mus/public/interfaces/window_manager.mojom b/components/mus/public/interfaces/window_manager.mojom
index 724c7acbf680efc4807d5e39154865ad95c622b2..11cf1fe6ed0c3f287e703da2ecb12e9df453fdf5 100644
--- a/components/mus/public/interfaces/window_manager.mojom
+++ b/components/mus/public/interfaces/window_manager.mojom
@@ -32,6 +32,9 @@ interface WindowManager {
   const string kShowState_Property = "prop:show-state";
   // The window bounds as set by user input. Type: gfx::Rect.
   const string kUserSetBounds_Property = "prop:user-set-bounds";
+  // The window's app icon. Type: SkBitmap
+  const string kWindowAppIcon_Property = "prop:window-app-icon";
+  // The window type. Type: mojom::WindowType
   const string kWindowType_Property = "prop:window-type";
   // The window's title. Type: mojom::String
   const string kWindowTitle_Property = "prop:window-title";