Support uninstalling ARC app from Chrome launcher

components/arc/common/app.mojom

 // Copyright 2015 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 module arc;
 
 // Duplicates ui::ScaleFactor enum in order to be accessible on Android side.
 enum ScaleFactor {
   SCALE_FACTOR_NONE = 0,
   SCALE_FACTOR_100P,
   SCALE_FACTOR_125P,
   SCALE_FACTOR_133P,
   SCALE_FACTOR_140P,
   SCALE_FACTOR_150P,
   SCALE_FACTOR_180P,
   SCALE_FACTOR_200P,
   SCALE_FACTOR_250P,
   SCALE_FACTOR_300P,
 
   NUM_SCALE_FACTORS
 };
 
 // Describes ARC app.
 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.
 struct ScreenRect {
   int32 left;
   int32 top;
   int32 right;
   int32 bottom;
 };
 
@@ skipping 40 matching lines @@
   // Sends a request to ARC for the ARC app icon of a required scale factor.
   // Scale factor is an enum defined at ui/base/layout.h. App is defined by
   // |package_name| and |activity|, which cannot be empty.
   RequestAppIcon(string package_name, string activity,
                  ScaleFactor scale_factor);
 
   // Query if a given resolution can be handled by the application. Returns true
   // 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);
 };