Support uninstalling ARC app from Chrome launcher

components/arc/common/app.mojom

Index: components/arc/common/app.mojom
diff --git a/components/arc/common/app.mojom b/components/arc/common/app.mojom
index b18adbe138643af0212a8b4001fb0c4ebfa7b15f..add3907f68980c4123a7561c45ad52f77410de1c 100644
--- a/components/arc/common/app.mojom
+++ b/components/arc/common/app.mojom
@@ -25,6 +25,7 @@ struct AppInfo {
   string name;
   string package_name;
   string activity;
+  [MinVersion=2] bool sticky;  // true if the app cannot be uninstalled
 };
 
 // Represents a rectangle to specify screen coordinates.
@@ -85,4 +86,8 @@ interface AppInstance {
   // if it can.
   [MinVersion=1] CanHandleResolution(string package_name, string activity,
                                      ScreenRect dimension) => (bool success);
+
+  // Sends a request to ARC to uninstall the given app.  Error message (UTF-8
+  // string), or null if succeeds, is returned via the callback.
+  [MinVersion=2] UninstallApp(string package) => (string error_message);
 };