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 uninstallable;
 };
 
 // Represents a rectangle to specify screen coordinates.
 struct ScreenRect {
   int32 left;
   int32 top;
   int32 right;
   int32 bottom;
 };
 
@@ skipping 12 matching lines @@
   // app.
   [MinVersion=1] OnPackageRemoved@3(string package_name);
 
   // Receives an icon of required |scale_factor| for specific ARC app. The app
   // is defined by |package_name| and |activity|. The icon content cannot be
   // empty and must match to |scale_factor| assuming 48x48 for
   // SCALE_FACTOR_100P.  |scale_factor| is an enum defined at ui/base/layout.h.
   // |icon_png_data| is a png-encoded image.
   OnAppIcon@1(string package_name, string activity,
               ScaleFactor scale_factor, array<uint8> icon_png_data);
+
+  // Sends the error message (null if succeeds) to the host.
+  [MinVersion=2] OnUninstallAppResponse@4(string error_message);
 };
 
 // TODO(lhchavez): Migrate all request/response messages to Mojo.
 interface AppInstance {
   Init(AppHost host_ptr);
 
   // Sends a request to ARC to launch an ARC app defined by |package_name| and
   // |activity|, which cannot be empty. |dimension_on_screen| can be null to
   // indicate to use the entire screen.
   LaunchApp(string package_name, string activity,
             [MinVersion=1] ScreenRect? dimension);
 
   // Sends a request to ARC to refresh a list of ARC apps.
   // OnRefreshAppsList is expected in response to this message. However,
   // response may not be sent if ARC is not ready yet (boot completed event is
   // not received).
   RefreshAppList();
 
   // 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.  Response will be
+  // returned via AppHost.OnUninstallAppResponse.
+  [MinVersion=2] UninstallApp(string package);

[Luis Héctor Chávez, 2016/03/04 21:29:37]

Can you instead do

[MinVersion=2] UninstallApp(string package) => (string error_message);

? That is probably going to simplify some stuff.

[khmel, 2016/03/04 22:02:40]

Do we really want sync method? This is UI thread. IMHO we should do async here

[Luis Héctor Chávez, 2016/03/04 22:05:15]

Mojo has no support for sync IPC. This is async :) A second parameter to
UninstallApp() when invoked from C++ will be a
base::Callback<void(mojo::String)>.

[victorhsieh0, 2016/03/07 21:00:16]

Done.

 };