gpu: Add a couple of unit-tests for GpuService.

services/ui/gpu/gpu_service_unittest.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 "services/ui/gpu/gpu_service.h"
+
+#include "base/macros.h"
+#include "base/memory/ptr_util.h"
+#include "base/memory/weak_ptr.h"
+#include "base/message_loop/message_loop.h"
+#include "base/run_loop.h"
+#include "gpu/config/gpu_info.h"
+#include "gpu/ipc/service/gpu_watchdog_thread.h"
+#include "services/ui/public/interfaces/gpu.mojom.h"
+#include "testing/gtest/include/gtest/gtest.h"
+
+namespace ui {
+namespace test {
+
+class GpuServiceTest : public testing::Test {
+ public:
+  GpuServiceTest()
+      : io_thread_("TestIOThread"),
+        wait_(base::WaitableEvent::ResetPolicy::MANUAL,
+              base::WaitableEvent::InitialState::NOT_SIGNALED) {}
+  ~GpuServiceTest() override {}
+
+  GpuService* gpu_service() { return gpu_service_.get(); }
+
+  void DestroyService() { gpu_service_ = nullptr; }
+
+  void BlockIOThread() {
+    wait_.Reset();
+    io_runner()->PostTask(FROM_HERE, base::Bind(&base::WaitableEvent::Wait,
+                                                base::Unretained(&wait_)));
+  }
+
+  void UnblockIOThread() {
+    DCHECK(!wait_.IsSignaled());
+    wait_.Signal();
+  }
+
+  scoped_refptr<base::SingleThreadTaskRunner> io_runner() {
+    return io_thread_.task_runner();
+  }
+
+  // testing::Test
+  void SetUp() override {
+    ASSERT_TRUE(io_thread_.Start());
+    gpu_service_ = base::MakeUnique<GpuService>(
+        gpu::GPUInfo(), nullptr /* watchdog_thread */, io_thread_.task_runner(),
+        gpu::GpuFeatureInfo());
+  }
+
+  void TearDown() override {
+    DestroyService();
+    base::RunLoop runloop;
+    runloop.RunUntilIdle();
+    io_thread_.Stop();
+  }
+
+ private:
+  base::MessageLoop message_loop_;
+  base::Thread io_thread_;
+  std::unique_ptr<GpuService> gpu_service_;
+  base::WaitableEvent wait_;
+
+  DISALLOW_COPY_AND_ASSIGN(GpuServiceTest);
+};
+
+// Tests that GpuService can be destroyed before Bind() succeeds on the IO
+// thread.
+TEST_F(GpuServiceTest, ServiceDestroyedBeforeBind) {
+  mojom::GpuServicePtr ptr;
+  mojom::GpuServiceRequest request(&ptr);
+
+  // Block the IO thread to make sure that the GpuService is destroyed before
+  // the binding happens on the IO thread.
+  BlockIOThread();
+  gpu_service()->Bind(std::move(request));
+  DestroyService();
+  UnblockIOThread();
+}
+
+// Tests ghat GpuService can be destroyed after Bind() succeeds on the IO
+// thread.
+TEST_F(GpuServiceTest, ServiceDestroyedAfterBind) {
+  mojom::GpuServicePtr ptr;
+  mojom::GpuServiceRequest request(&ptr);
+  gpu_service()->Bind(std::move(request));
+  base::WaitableEvent wait(base::WaitableEvent::ResetPolicy::MANUAL,
+                           base::WaitableEvent::InitialState::NOT_SIGNALED);
+  io_runner()->PostTask(FROM_HERE, base::Bind(&base::WaitableEvent::Signal,
+                                              base::Unretained(&wait)));
+  wait.Wait();
+  DestroyService();
+}
+
+}  // namespace test
+}  // namespace ui