components: Prepare unittests for PostTask refactor.

This adds TestBrowserThreadBundles to unittests that will need it when
we replace BrowserThread::PostTask() and friends with base/post_task.h.

The TestBrowserThreadBundle initializes globals that are required for
things like posting a task to or obtaining a TaskRunner for a BrowserThread.

I'm making this change in a separate patch to make review of the
future automated refactoring patches easier.

Depends on https://crrev.com/c/1185887.

Bug: 878356
Change-Id: Ifd332b995e3449b26d9c93283fb708792b2e66eb
Reviewed-on: https://chromium-review.googlesource.com/1208050Reviewed-by: Derek Cheng <imcheng@chromium.org>
Reviewed-by: Jialiu Lin <jialiul@chromium.org>
Commit-Queue: Eric Seckler <eseckler@chromium.org>
Cr-Commit-Position: refs/heads/master@{#589613}

components/cast_channel/cast_message_handler_unittest.cc

@@ -10,6 +10,7 @@
 #include "base/test/scoped_task_environment.h"
 #include "base/test/test_simple_task_runner.h"
 #include "components/cast_channel/cast_test_util.h"
+#include "content/public/test/test_browser_thread_bundle.h"
 #include "services/data_decoder/public/cpp/testing_json_parser.h"
 #include "services/service_manager/public/cpp/connector.h"
 #include "testing/gmock/include/gmock/gmock.h"
@@ -56,6 +57,7 @@ class CastMessageHandlerTest : public testing::Test {
   CastMessageHandlerTest()
       : environment_(
             base::test::ScopedTaskEnvironment::MainThreadType::MOCK_TIME),
+        thread_bundle_(content::TestBrowserThreadBundle::PLAIN_MAINLOOP),
         cast_socket_service_(new base::TestSimpleTaskRunner()),
         handler_(&cast_socket_service_,
                  /* connector */ nullptr,
@@ -98,6 +100,7 @@ class CastMessageHandlerTest : public testing::Test {
 
  protected:
   base::test::ScopedTaskEnvironment environment_;
+  content::TestBrowserThreadBundle thread_bundle_;
   std::unique_ptr<base::RunLoop> run_loop_;
   MockCastSocketService cast_socket_service_;
   data_decoder::TestingJsonParser::ScopedFactoryOverride parser_override_;

components/cast_channel/cast_socket_service_unittest.cc

@@ -36,6 +36,7 @@ class CastSocketServiceTest : public testing::Test {
   void TearDown() override { cast_socket_service_ = nullptr; }
 
  protected:
+  content::TestBrowserThreadBundle thread_bundle_;
   std::unique_ptr<CastSocketService> cast_socket_service_;
   base::MockCallback<CastSocket::OnOpenCallback> mock_on_open_callback_;
   MockCastSocketObserver mock_observer_;

components/safe_browsing/db/whitelist_checker_client_unittest.cc

@@ -6,15 +6,13 @@
 #include <memory>
 
 #include "base/bind.h"
-#include "base/message_loop/message_loop.h"
-#include "base/message_loop/message_loop_current.h"
 #include "base/run_loop.h"
 #include "base/test/mock_callback.h"
-#include "base/test/test_mock_time_task_runner.h"
+#include "base/test/scoped_task_environment.h"
 #include "base/threading/thread_task_runner_handle.h"
 #include "components/safe_browsing/db/test_database_manager.h"
 #include "content/public/browser/browser_thread.h"
-#include "content/public/test/test_browser_thread.h"
+#include "content/public/test/test_browser_thread_bundle.h"
 #include "testing/gmock/include/gmock/gmock.h"
 #include "testing/gtest/include/gtest/gtest.h"
 
@@ -48,16 +46,14 @@ class MockSafeBrowsingDatabaseManager : public TestSafeBrowsingDatabaseManager {
 
 class WhitelistCheckerClientTest : public testing::Test {
  public:
-  WhitelistCheckerClientTest() : target_url_("http://foo.bar") {}
+  WhitelistCheckerClientTest()
+      : environment_(
+            base::test::ScopedTaskEnvironment::MainThreadType::MOCK_TIME),
+        thread_bundle_(content::TestBrowserThreadBundle::PLAIN_MAINLOOP),
+        target_url_("http://foo.bar") {}
 
   void SetUp() override {
     database_manager_ = new MockSafeBrowsingDatabaseManager;
-    task_runner_ = new base::TestMockTimeTaskRunner(base::Time::Now(),
-                                                    base::TimeTicks::Now());
-    message_loop_.reset(new base::MessageLoop);
-    io_thread_ = std::make_unique<content::TestBrowserThread>(
-        content::BrowserThread::IO, base::MessageLoopCurrent::Get());
-    message_loop_->SetTaskRunner(task_runner_);
   }
 
   void TearDown() override {
@@ -67,18 +63,15 @@ class WhitelistCheckerClientTest : public testing::Test {
     // Verify no callback is remaining.
     // TODO(nparker): We should somehow EXPECT that no entry is remaining,
     // rather than just invoking it.
-    task_runner_->FastForwardUntilNoTasksRemain();
+    environment_.FastForwardUntilNoTasksRemain();
   }
 
  protected:
+  base::test::ScopedTaskEnvironment environment_;
+  content::TestBrowserThreadBundle thread_bundle_;
+
   GURL target_url_;
   scoped_refptr<MockSafeBrowsingDatabaseManager> database_manager_;
-
-  // Needed for |database_manager_| teardown tasks.
-  std::unique_ptr<content::TestBrowserThread> io_thread_;
-
-  std::unique_ptr<base::MessageLoop> message_loop_;
-  scoped_refptr<base::TestMockTimeTaskRunner> task_runner_;
 };
 
 TEST_F(WhitelistCheckerClientTest, TestMatch) {
@@ -125,11 +118,11 @@ TEST_F(WhitelistCheckerClientTest, TestAsyncTimeout) {
   MockBoolCallback callback;
   WhitelistCheckerClient::StartCheckCsdWhitelist(database_manager_, target_url_,
                                                  callback.Get());
-  task_runner_->FastForwardBy(base::TimeDelta::FromSeconds(1));
+  environment_.FastForwardBy(base::TimeDelta::FromSeconds(1));
   // No callback yet.
 
   EXPECT_CALL(callback, Run(true /* is_whitelisted */));
-  task_runner_->FastForwardBy(base::TimeDelta::FromSeconds(5));
+  environment_.FastForwardBy(base::TimeDelta::FromSeconds(5));
 }
 
 }  // namespace safe_browsing

components/safe_browsing/triggers/ad_sampler_trigger_unittest.cc

@@ -226,6 +226,7 @@ TEST(AdSamplerTriggerTestFinch, FrequencyDenominatorFeature) {
   // Make sure that setting the frequency denominator via Finch params works as
   // expected, and that the default frequency is used when no Finch config is
   // given.
+  content::TestBrowserThreadBundle thread_bundle;
   AdSamplerTrigger trigger_default(nullptr, nullptr, nullptr, nullptr, nullptr);
   EXPECT_EQ(kAdSamplerDefaultFrequency,
             trigger_default.sampler_frequency_denominator_);