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..0b3ecbf3db0c739e9e40e3c10ba004605fd10782 100644
--- a/components/arc/test/fake_app_instance.cc
+++ b/components/arc/test/fake_app_instance.cc
@@ -105,6 +105,16 @@ void FakeAppInstance::SendTaskCreated(int32_t taskId,
                            intent);
 }
 
+void FakeAppInstance::SendTaskDescription(
+    int32_t taskId,
+    const std::string& label,
+    const std::string& icon_png_data_as_string) {
+  app_host_->OnTaskDescriptionUpdated(
+      taskId, label,
+      std::vector<uint8_t>(icon_png_data_as_string.begin(),
+                           icon_png_data_as_string.end()));
+}
+
 void FakeAppInstance::SendTaskDestroyed(int32_t taskId) {
   app_host_->OnTaskDestroyed(taskId);
 }