content: implement unittests backend for Ozone GBM

ui/ozone/public/ozone_gpu_test_helper.cc

 // Copyright 2014 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 "ui/ozone/public/ozone_gpu_test_helper.h"
 
+#include "base/message_loop/message_loop.h"
+#include "base/run_loop.h"
 #include "base/thread_task_runner_handle.h"
 #include "ipc/ipc_listener.h"
 #include "ipc/ipc_message.h"
 #include "ipc/ipc_sender.h"
 #include "ipc/message_filter.h"
 #include "ui/ozone/public/gpu_platform_support.h"
 #include "ui/ozone/public/gpu_platform_support_host.h"
 #include "ui/ozone/public/ozone_platform.h"
 
 namespace ui {
@@ skipping 88 matching lines @@
       FROM_HERE, base::Bind(&FakeGpuProcess::InitOnIO,
                             base::Unretained(fake_gpu_process_.get())));
   fake_gpu_process_->Init();
 
   fake_gpu_process_host_.reset(new FakeGpuProcessHost(gpu_task_runner));
   fake_gpu_process_host_->Init();
 
   return true;
 }
 
+// static
+scoped_ptr<OzoneInitializerForTest> OzoneInitializerForTest::Create() {
+  scoped_ptr<OzoneInitializerForTest> self(new OzoneInitializerForTest());
+  if (!self->Initialize())
+    return nullptr;
+  return self.Pass();
+}
+
+OzoneInitializerForTest::OzoneInitializerForTest() {
+}
+
+OzoneInitializerForTest::~OzoneInitializerForTest() {
+}
+
+bool OzoneInitializerForTest::Initialize() {
+  scoped_ptr<base::MessageLoop> message_loop;
+  if (!base::MessageLoop::current())
+    message_loop.reset(new base::MessageLoopForUI);

[dshwang, 2015/07/15 16:02:41]

MessageLoopForUI creation is ugly, but OzonePlatform::InitializeForGPU() in gbm
ozone requires message loop.

This is called in this stack. At the time, message loop is not created.

#2 0x00000114fa33 content::ContentTestSuite::Initialize()
#3 0x00000118319b base::TestSuite::Run()
#4 0x00000117ceef base::(anonymous namespace)::LaunchUnitTestsInternal()
#5 0x00000117d416 base::LaunchUnitTests()

Later, some unittests create message loop in ad-hoc manner.
#1 0x7f3f2f6c15cd base::MessageLoop::MessageLoop()
#2 0x00000114b255 content::TestBrowserThreadBundle::Init()
#3 0x00000114d780 content::RenderViewHostTestHarness::SetUp()
#4 0x00000093cba6 content::NavigatorTestWithBrowserSideNavigation::SetUp()
#5 0x0000011ba3a9 testing::Test::Run()
#6 0x0000011ba598 testing::TestInfo::Run()
#7 0x0000011ba6ed testing::TestCase::Run()
#8 0x0000011bbaed testing::internal::UnitTestImpl::RunAllTests()
#9 0x0000011bbd15 testing::UnitTest::Run()
#10 0x00000118323d base::TestSuite::Run()
#11 0x00000117ceef base::(anonymous namespace)::LaunchUnitTestsInternal()
#12 0x00000117d416 base::LaunchUnitTests()

I think it's natural for ContentTestSuite to create message loop, but
refactoring TestBrowserThreadBundle or RenderViewHostTestHarness supposed to be
very huge change.

vignatti had the similar issue before,
https://codereview.chromium.org/1043233003/
spang, vignatti, WDYT?

[dshwang, 2015/07/15 16:07:19]

another solution is to move `gfx::GLSurface::InitializeOneOffForTests()` from
ContentTestSuite to each test such as TestBrowserThreadBundle.

+
+  OzonePlatform::InitializeForUI();
+  OzonePlatform::InitializeForGPU();
+  gpu_helper_.reset(new OzoneGpuTestHelper);
+  if (!gpu_helper_->Initialize(base::ThreadTaskRunnerHandle::Get(),
+                               base::ThreadTaskRunnerHandle::Get())) {
+    return false;
+  }
+  {
+    base::MessageLoop::ScopedNestableTaskAllower allow(
+        base::MessageLoop::current());
+    base::RunLoop().RunUntilIdle();
+  }
+  return true;
+}
+
 }  // namespace ui