Reland "Add basic ServiceConnection unit test"

This is a reland of 453eba23

Removed the call to mojo::core::Init from the test startup. It
caused a memory leak because //chromeos/run_all_unittests.cc
already calls it.

Original change's description:
> Add basic ServiceConnection unit test
>
> The is just testing that ServiceConnection::BindModelProvider returns
> successfully. The Mojo invitation won't go anywhere beyond the no-op
> FakeMachineLearningClient D-Bus client.
>
> To make this test compile, I had to fix an #include from an
> overlooked file rename in an earlier CL ...
>
> Bug: 863794
>
> Change-Id: Ifd31fea950145561cd5954ae16e930b801bfe49b
> Reviewed-on: https://chromium-review.googlesource.com/1139942
> Commit-Queue: Andrew Moylan <amoylan@chromium.org>
> Reviewed-by: Ken Rockot <rockot@chromium.org>
> Reviewed-by: Dan Erat <derat@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#578329}

Tested by: manual detect_leaks=1 invocation of the test.

TBR=rockot@chromium.org,derat@chromium.org

Bug: 863794
Change-Id: I1258de74273551cebdc9dd1a76f86a35ffa50147
Reviewed-on: https://chromium-review.googlesource.com/1154647Reviewed-by: Andrew Moylan <amoylan@chromium.org>
Commit-Queue: Andrew Moylan <amoylan@chromium.org>
Cr-Commit-Position: refs/heads/master@{#579234}

chromeos/dbus/fake_machine_learning_client.cc

@@ -15,7 +15,7 @@ void FakeMachineLearningClient::Init(dbus::Bus* const bus) {}
 void FakeMachineLearningClient::BootstrapMojoConnection(
     base::ScopedFD fd,
     base::OnceCallback<void(bool success)> result_callback) {
-  const bool success = false;
+  const bool success = true;
   std::move(result_callback).Run(success);
 }
 

chromeos/services/BUILD.gn

@@ -22,6 +22,7 @@ source_set("unit_tests") {
   testonly = true
   deps = [
     "//chromeos/services/device_sync:unit_tests",
+    "//chromeos/services/machine_learning/public/cpp:unit_tests",
     "//chromeos/services/multidevice_setup:unit_tests",
     "//chromeos/services/secure_channel:unit_tests",
   ]

chromeos/services/machine_learning/DEPS

 include_rules = [
   "+chromeos/dbus",
+  "+mojo/core/embedder",
   "+mojo/public",
 ]

chromeos/services/machine_learning/public/cpp/BUILD.gn

@@ -15,3 +15,19 @@ source_set("cpp") {
     "//chromeos/services/machine_learning/public/mojom",
   ]
 }
+
+source_set("unit_tests") {
+  testonly = true
+  sources = [
+    "service_connection_unittest.cc",
+  ]
+  deps = [
+    ":cpp",
+    "//base/test:test_support",
+    "//chromeos",
+    "//chromeos/services/machine_learning/public/mojom",
+    "//mojo/core/embedder",
+    "//mojo/public/cpp/bindings",
+    "//testing/gtest",
+  ]
+}

chromeos/services/machine_learning/public/cpp/service_connection.cc

@@ -7,7 +7,7 @@
 #include "base/no_destructor.h"
 #include "chromeos/dbus/dbus_thread_manager.h"
 #include "chromeos/dbus/machine_learning_client.h"
-#include "chromeos/services/machine_learning/public/mojom/interface.mojom.h"
+#include "chromeos/services/machine_learning/public/mojom/machine_learning_service.mojom.h"
 #include "mojo/public/cpp/platform/platform_channel.h"
 #include "mojo/public/cpp/system/invitation.h"
 #include "third_party/cros_system_api/dbus/service_constants.h"

chromeos/services/machine_learning/public/cpp/service_connection.h

@@ -8,7 +8,7 @@
 #include "base/macros.h"
 #include "base/no_destructor.h"
 #include "base/sequence_checker.h"
-#include "chromeos/services/machine_learning/public/mojom/interface.mojom.h"
+#include "chromeos/services/machine_learning/public/mojom/machine_learning_service.mojom.h"
 
 namespace chromeos {
 namespace machine_learning {

chromeos/services/machine_learning/public/cpp/service_connection_unittest.cc

+// Copyright 2018 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 "chromeos/services/machine_learning/public/cpp/service_connection.h"
+
+#include "base/macros.h"
+#include "base/test/scoped_task_environment.h"
+#include "base/threading/thread.h"
+#include "chromeos/dbus/dbus_thread_manager.h"
+#include "chromeos/services/machine_learning/public/mojom/machine_learning_service.mojom.h"
+#include "mojo/core/embedder/embedder.h"
+#include "mojo/core/embedder/scoped_ipc_support.h"
+#include "mojo/public/cpp/bindings/interface_request.h"
+#include "testing/gtest/include/gtest/gtest.h"
+
+namespace chromeos {
+namespace machine_learning {
+namespace {
+
+class ServiceConnectionTest : public testing::Test {
+ public:
+  ServiceConnectionTest() = default;
+
+ protected:
+  static void SetUpTestCase() {
+    DBusThreadManager::Initialize();
+
+    static base::Thread ipc_thread("ipc");
+    ipc_thread.StartWithOptions(
+        base::Thread::Options(base::MessageLoop::TYPE_IO, 0));
+    static mojo::core::ScopedIPCSupport ipc_support(
+        ipc_thread.task_runner(),
+        mojo::core::ScopedIPCSupport::ShutdownPolicy::CLEAN);
+  }
+
+ private:
+  base::test::ScopedTaskEnvironment scoped_task_environment_;
+
+  DISALLOW_COPY_AND_ASSIGN(ServiceConnectionTest);
+};
+
+// Tests that BindModelProvider runs OK (no crash) in a basic Mojo environment.
+TEST_F(ServiceConnectionTest, BindModelProvider) {
+  mojom::ModelProviderPtr model_provider;
+  ServiceConnection::GetInstance()->BindModelProvider(
+      mojo::MakeRequest(&model_provider));
+}
+
+}  // namespace
+}  // namespace machine_learning
+}  // namespace chromeos