Use spin runloop instead of WaitForIncomingMethodCall() for test codes.

components/arc/test/fake_arc_bridge_instance.h

 // 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.
 
 #ifndef COMPONENTS_ARC_TEST_FAKE_ARC_BRIDGE_INSTANCE_H_
 #define COMPONENTS_ARC_TEST_FAKE_ARC_BRIDGE_INSTANCE_H_
 
+#include "base/callback_forward.h"
 #include "base/macros.h"
 #include "components/arc/arc_bridge_service.h"
 #include "components/arc/common/arc_bridge.mojom.h"
 #include "mojo/public/cpp/bindings/binding.h"
 
 namespace arc {
 
 class FakeArcBridgeInstance : public mojom::ArcBridgeInstance {
  public:
   class Delegate {
@@ skipping 22 matching lines @@
 
   // The number of times Init() has been called.
   int init_calls() const { return init_calls_; }
 
   // Stops the instance.
   void Stop(ArcBridgeService::StopReason reason);
 
  private:
   Delegate* delegate_ = nullptr;
 
+  // Keeps quit closure to wake the running nested RunLoop.
+  base::Closure quit_closure_;
+
   // Mojo endpoints.
   mojo::Binding<mojom::ArcBridgeInstance> binding_;
   mojom::ArcBridgeHostPtr host_ptr_;
   int init_calls_ = 0;
 
   DISALLOW_COPY_AND_ASSIGN(FakeArcBridgeInstance);
 };
 
 }  // namespace arc
 
 #endif  // COMPONENTS_ARC_TEST_FAKE_ARC_BRIDGE_INSTANCE_H_