[Power: ML]: Remove remaining uses of TestMockTimeTaskRunner

ScopedTaskEnvironment is sufficient for the purposes of power/ml
unit tests, so remove usages of TestMockTimeTaskRunner. This also
removes need to support both TestMockTimeTaskRunner *and*
ScopedTaskEnvironment in FakeBookClock.

Bug: 917580
Test: All related unit tests still pass.

Change-Id: Iec413bf52422a12462f8ff99ef5e02e23907925a
Reviewed-on: https://chromium-review.googlesource.com/c/1393896Reviewed-by: Jia Meng <jiameng@chromium.org>
Commit-Queue: Prashant Malani <pmalani@chromium.org>
Cr-Commit-Position: refs/heads/master@{#619877}

chrome/browser/chromeos/power/ml/adaptive_screen_brightness_manager_unittest.cc

@@ -82,21 +82,24 @@ class AdaptiveScreenBrightnessManagerTest
     : public ChromeRenderViewHostTestHarness {
  public:
   AdaptiveScreenBrightnessManagerTest()
-      : task_runner_(base::MakeRefCounted<base::TestMockTimeTaskRunner>()) {
+      : ChromeRenderViewHostTestHarness(
+            base::test::ScopedTaskEnvironment::MainThreadType::UI_MOCK_TIME,
+            base::test::ScopedTaskEnvironment::ExecutionMode::QUEUED,
+            content::TestBrowserThreadBundle::Options::DEFAULT) {
     auto logger = std::make_unique<TestingAdaptiveScreenBrightnessUkmLogger>();
     ukm_logger_ = logger.get();
 
     fake_power_manager_client_.Init(nullptr);
     viz::mojom::VideoDetectorObserverPtr observer;
     auto periodic_timer = std::make_unique<base::RepeatingTimer>();
-    periodic_timer->SetTaskRunner(task_runner_);
+    periodic_timer->SetTaskRunner(thread_bundle()->GetMainThreadTaskRunner());
     screen_brightness_manager_ =
         std::make_unique<AdaptiveScreenBrightnessManager>(
             std::move(logger), &user_activity_detector_,
             &fake_power_manager_client_, nullptr, nullptr,
             mojo::MakeRequest(&observer), std::move(periodic_timer),
-            task_runner_->GetMockClock(),
-            std::make_unique<FakeBootClock>(task_runner_,
+            const_cast<base::Clock*>(thread_bundle()->GetMockClock()),
+            std::make_unique<FakeBootClock>(thread_bundle(),
                                             base::TimeDelta::FromSeconds(10)));
   }
 
@@ -150,7 +153,7 @@ class AdaptiveScreenBrightnessManagerTest
   }
 
   void FastForwardTimeBySecs(const int seconds) {
-    task_runner_->FastForwardBy(base::TimeDelta::FromSeconds(seconds));
+    thread_bundle()->FastForwardBy(base::TimeDelta::FromSeconds(seconds));
   }
 
   // Creates a test browser window and sets its visibility, activity and
@@ -217,9 +220,6 @@ class AdaptiveScreenBrightnessManagerTest
   const GURL kUrl3 = GURL("https://example3.com/");
 
  private:
-  // TODO(crbug.com/917580): Remove this; thread_bundle() should be used
-  // instead.
-  const scoped_refptr<base::TestMockTimeTaskRunner> task_runner_;
   chromeos::FakeChromeUserManager fake_user_manager_;
 
   ui::UserActivityDetector user_activity_detector_;

chrome/browser/chromeos/power/ml/fake_boot_clock.cc

@@ -8,16 +8,6 @@ namespace chromeos {
 namespace power {
 namespace ml {
 
-FakeBootClock::FakeBootClock(
-    scoped_refptr<const base::TestMockTimeTaskRunner> task_runner,
-    base::TimeDelta initial_time_since_boot)
-    : task_runner_(task_runner),
-      env_(nullptr),
-      initial_time_since_boot_(initial_time_since_boot) {
-  DCHECK_GE(initial_time_since_boot, base::TimeDelta());
-  initial_time_ticks_ = task_runner_->NowTicks();
-}
-
 FakeBootClock::FakeBootClock(base::test::ScopedTaskEnvironment* env,
                              base::TimeDelta initial_time_since_boot)
     : env_(env), initial_time_since_boot_(initial_time_since_boot) {
@@ -28,12 +18,7 @@ FakeBootClock::FakeBootClock(base::test::ScopedTaskEnvironment* env,
 FakeBootClock::~FakeBootClock() = default;
 
 base::TimeDelta FakeBootClock::GetTimeSinceBoot() {
-  base::TimeTicks now;
-  if (env_) {
-    now = env_->NowTicks();
-  } else {
-    now = task_runner_->NowTicks();
-  }
+  base::TimeTicks now = env_->NowTicks();
   return (now - initial_time_ticks_) + initial_time_since_boot_;
 }
 

chrome/browser/chromeos/power/ml/fake_boot_clock.h

@@ -18,8 +18,6 @@ namespace ml {
 
 class FakeBootClock : public BootClock {
  public:
-  FakeBootClock(scoped_refptr<const base::TestMockTimeTaskRunner> task_runner,
-                base::TimeDelta initial_time_since_boot);
   FakeBootClock(base::test::ScopedTaskEnvironment* env,
                 base::TimeDelta initial_time_since_boot);
   ~FakeBootClock() override;
@@ -28,9 +26,6 @@ class FakeBootClock : public BootClock {
   base::TimeDelta GetTimeSinceBoot() override;
 
  private:
-  // TODO(crbug.com/917580): This is no longer needed and should be removed.
-  // |env_| should give sufficient access to fake clock values.
-  scoped_refptr<const base::TestMockTimeTaskRunner> task_runner_;
   base::test::ScopedTaskEnvironment* env_;
   base::TimeDelta initial_time_since_boot_;
   base::TimeTicks initial_time_ticks_;