arc: Handle non-launchable apps.

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 1110e41be5e13f19a61d2622d38834cb6105214f..7abf3fe07f59349a01792bd0c80dff27325e52f6 100644
--- a/components/arc/common/app.mojom
+++ b/components/arc/common/app.mojom
@@ -2,7 +2,7 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 //
-// Next MinVersion: 13
+// Next MinVersion: 14
 
 module arc.mojom;
 
@@ -56,7 +56,7 @@ enum ShowPackageInfoPage {
   MANAGE_LINKS = 1,
 };
 
-// Next method ID: 13
+// Next method ID: 14
 interface AppHost {
   // Sends newly added ARC app to Chrome. This message is sent when ARC receives
   // package added notification. Multiple apps may be added in the one package.
@@ -91,8 +91,10 @@ interface AppHost {
   [MinVersion=1] OnPackageRemoved@3(string package_name);
 
   // Sends information about newly created task.
-  [MinVersion=4] OnTaskCreated@4(int32 task_id, string package_name,
-                                 string activity);
+  [MinVersion=4] OnTaskCreated@4(int32 task_id,

[Luis Héctor Chávez, 2016/08/10 17:48:53]

FYI: I was able to add the field in the middle by adding ordinals to every
field:

[MinVersion=4] OnTaskCreated@4(int32 task_id@0,
                               string package_name@1,
                               [MinVersion=13] string? name@3,
                               string activity@2);

up to you if you want to keep this ordering or the one you preferred originally.
In any case, please add explicit ordinals to all parameters.

+                                 string package_name,
+                                 string activity,
+                                 [MinVersion=13] string? name);
 
   // Notifies that task has been destroyed.
   [MinVersion=4] OnTaskDestroyed@5(int32 task_id);