arc-bridge: Expose the Mojo version number of the interfaces

components/arc/test/fake_app_instance.cc

 // 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.
 
 #include "components/arc/test/fake_app_instance.h"
 
 #include <stdint.h>
 
 #include <string>
 #include <vector>
 
 #include "base/files/file_path.h"
 #include "base/files/file_util.h"
 #include "base/path_service.h"
+#include "base/run_loop.h"
 #include "mojo/common/common_type_converters.h"
 
 namespace mojo {
 
 template <>
 struct TypeConverter<arc::AppInfoPtr, arc::AppInfo> {
   static arc::AppInfoPtr Convert(const arc::AppInfo& app_info) {
     return app_info.Clone();
   }
 };
@@ skipping 77 matching lines @@
                        mojo::Array<uint8_t>::From(*png_data_as_string));
 
   return true;
 }
 
 void FakeAppInstance::WaitForIncomingMethodCall() {
   binding_.WaitForIncomingMethodCall();
 }
 
 void FakeAppInstance::WaitForOnAppInstanceReady() {
-  WaitForIncomingMethodCall();  // Wait for Init().
-  WaitForIncomingMethodCall();  // Wait for RefreshAppList().
+  // Several messages are sent back and forth when OnAppInstanceReady() is
+  // called. Normally, it would be preferred to use a single
+  // WaitForIncomingMethodCall() to wait for each method individually, but
+  // QueryVersion() does require processing on the I/O thread, so
+  // RunUntilIdle() is required to correctly dispatch it. On slower machines
+  // (and when running under Valgrind), the two thread hops needed to send and
+  // dispatch each Mojo message might not be picked up by a single
+  // RunUntilIdle(), so keep pumping the message loop until all expected
+  // messages are.
+  while (refresh_app_list_count_ != 1) {
+    base::RunLoop().RunUntilIdle();
+  }
 }
 
 }  // namespace arc