arc: Set custom icon in shelf for ARC apps.

components/arc/test/fake_app_instance.cc

Index: components/arc/test/fake_app_instance.cc
diff --git a/components/arc/test/fake_app_instance.cc b/components/arc/test/fake_app_instance.cc
index cc0ced3be73e422563b2480e9873d18cb8bb0acd..3d4b8f7ec9a17d5e8e500e6ecca068825239036a 100644
--- a/components/arc/test/fake_app_instance.cc
+++ b/components/arc/test/fake_app_instance.cc
@@ -105,6 +105,14 @@ void FakeAppInstance::SendTaskCreated(int32_t taskId,
                            intent);
 }
 
+void FakeAppInstance::SendTaskDescription(int32_t taskId,
+                                          const std::string& label,
+                                          const std::string& icon_png_data) {
+  app_host_->OnTaskSetDescription(
+      taskId, label,
+      std::vector<uint8_t>(icon_png_data.begin(), icon_png_data.end()));
+}
+
 void FakeAppInstance::SendTaskDestroyed(int32_t taskId) {
   app_host_->OnTaskDestroyed(taskId);
 }