Add an end-to-end test that excercises Mojo with a sandbox.

content/shell/utility/mojo_test_impl.h

+// Copyright 2016 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 CONTENT_SHELL_UTILITY_MOJO_TEST_IMPL_H_
+#define CONTENT_SHELL_UTILITY_MOJO_TEST_IMPL_H_
+
+#include "content/common/mojo_test.mojom.h"
+#include "mojo/public/cpp/bindings/strong_binding.h"
+
+namespace content {
+
+// A service for testing Mojo end-to-end within a sandbox.
+class MojoTestImpl : public mojom::MojoTest {
+ public:
+  static void CreateMojoTestImpl(
+      mojo::InterfaceRequest<mojom::MojoTest> request);
+
+ private:
+  explicit MojoTestImpl(mojo::InterfaceRequest<mojom::MojoTest> request);
+  ~MojoTestImpl() override;
+
+  void MakeSharedBuffer(uint32_t size,
+                        const MakeSharedBufferCallback& callback) override;
+
+  mojo::StrongBinding<mojom::MojoTest> binding_;
+
+  DISALLOW_COPY_AND_ASSIGN(MojoTestImpl);
+};
+
+}  // namespace content
+
+#endif  // CONTENT_SHELL_UTILITY_MOJO_TEST_IMPL_H_