Add service unittest for WakeLockServiceImpl.

device/wake_lock/wake_lock_provider.cc

 // Copyright 2017 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 "device/wake_lock/wake_lock_provider.h"
 
 #include <utility>
 
+#include "device/wake_lock/fake_wake_lock_service_impl.h"
 #include "device/wake_lock/wake_lock_service_impl.h"
 #include "mojo/public/cpp/bindings/strong_binding.h"
 
 namespace device {
 
+bool WakeLockProvider::is_in_service_unittest_ = false;
+
 // static
 void WakeLockProvider::Create(
     mojom::WakeLockProviderRequest request,
     scoped_refptr<base::SingleThreadTaskRunner> file_task_runner,
     const WakeLockContextCallback& native_view_getter) {
   mojo::MakeStrongBinding(base::MakeUnique<WakeLockProvider>(
                               std::move(file_task_runner), native_view_getter),
                           std::move(request));
 }
 
@@ skipping 13 matching lines @@
       base::MakeUnique<WakeLockServiceContext>(context_id, file_task_runner_,
                                                native_view_getter_),
       std::move(request));
 }
 
 void WakeLockProvider::GetWakeLockWithoutContext(
     mojom::WakeLockType type,
     mojom::WakeLockReason reason,
     const std::string& description,
     mojom::WakeLockServiceRequest request) {
-  // WakeLockServiceImpl owns itself.
-  new WakeLockServiceImpl(std::move(request), type, reason, description,
-                          WakeLockServiceContext::WakeLockInvalidContextId,
-                          native_view_getter_, file_task_runner_);
+  if (is_in_service_unittest_) {
+    // Create a fake WakeLockServiceImpl for testing.
+    new FakeWakeLockServiceImpl(

[ke.he, 2017/06/04 10:33:45]

If we move the "WakeLockServiceImplForTesting" into services/device/wake_lock/,
we'll introduce a dependency on //services/ here.

In future we'll move the whole //device/wake_lock into //services/. How about
just leave it in //device/ for now? 

+        std::move(request), type, reason, description,
+        WakeLockServiceContext::WakeLockInvalidContextId, native_view_getter_,
+        file_task_runner_);
+  } else {
+    // WakeLockServiceImpl owns itself.
+    new WakeLockServiceImpl(std::move(request), type, reason, description,
+                            WakeLockServiceContext::WakeLockInvalidContextId,
+                            native_view_getter_, file_task_runner_);
+  }
 }
 
 }  // namespace device