Fix animation throughput reporter test flakiness

* I give up using mock time because it still doesn't drive
  begin frame correctly.
* Factor out the TestReporter as a ThroughputReporterTesterBase template.
* Changed animation_throughput_reporter_unittest to use it.
Bug: 1157649

Change-Id: I876167808bc6c11872de64bfc9bc6e4263592f1f
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2581519Reviewed-by: Robert Flack <flackr@chromium.org>
Reviewed-by: Xiyuan Xia <xiyuan@chromium.org>
Commit-Queue: Mitsuru Oshima <oshima@chromium.org>
Cr-Commit-Position: refs/heads/master@{#841281}

ui/compositor/BUILD.gn

@@ -151,6 +151,8 @@ static_library("test_support") {
     "test/test_suite.h",
     "test/test_utils.cc",
     "test/test_utils.h",
+    "test/throughput_report_checker.cc",
+    "test/throughput_report_checker.h",
   ]
 
   if (is_android) {

ui/compositor/test/animation_throughput_reporter_test_base.cc

@@ -47,14 +47,14 @@ void AnimationThroughputReporterTestBase::TearDown() {
 
 void AnimationThroughputReporterTestBase::Advance(
     const base::TimeDelta& delta) {
-#if BUILDFLAG(IS_CHROMEOS_ASH)
-  task_environment_.FastForwardBy(delta);
-#else
-  base::RunLoop run_loop;
+  run_loop_ = std::make_unique<base::RunLoop>();
   base::ThreadTaskRunnerHandle::Get()->PostDelayedTask(
-      FROM_HERE, run_loop.QuitClosure(), delta);
-  run_loop.Run();
-#endif
+      FROM_HERE, run_loop_->QuitClosure(), delta);
+  run_loop_->Run();
+}
+
+void AnimationThroughputReporterTestBase::QuitRunLoop() {
+  run_loop_->Quit();
 }
 
 }  // namespace ui

ui/compositor/test/animation_throughput_reporter_test_base.h

@@ -15,6 +15,10 @@
 #include "ui/compositor/layer.h"
 #include "ui/compositor/test/test_compositor_host.h"
 
+namespace base {
+class RunLoop;
+}
+
 namespace ui {
 class TestContextFactories;
 
@@ -39,13 +43,11 @@ class AnimationThroughputReporterTestBase : public testing::Test {
   // Advances the time by |delta|.
   void Advance(const base::TimeDelta& delta);
 
+  void QuitRunLoop();
+
  private:
   base::test::TaskEnvironment task_environment_{
-#if BUILDFLAG(IS_CHROMEOS_ASH)
-    base::test::TaskEnvironment::TimeSource::MOCK_TIME,
-#endif
-        base::test::TaskEnvironment::MainThreadType::UI
-  };
+      base::test::TaskEnvironment::MainThreadType::UI};
 
   std::unique_ptr<TestContextFactories> context_factories_;
   std::unique_ptr<TestCompositorHost> host_;
@@ -54,6 +56,8 @@ class AnimationThroughputReporterTestBase : public testing::Test {
   // A timer to generate continuous compositor frames to trigger throughput
   // data being transferred back.
   base::RepeatingTimer frame_generation_timer_;
+
+  std::unique_ptr<base::RunLoop> run_loop_;
 };
 
 }  // namespace ui

ui/compositor/test/throughput_report_checker.cc

+// Copyright 2020 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/compositor/test/throughput_report_checker.h"
+
+#include "base/time/time.h"
+#include "ui/compositor/test/animation_throughput_reporter_test_base.h"
+
+namespace ui {
+
+bool ThroughputReportChecker::WaitUntilReported() {
+  DCHECK(!reported_);
+  test_base_->Advance(base::TimeDelta::FromSeconds(5));
+  return reported_;
+}
+
+void ThroughputReportChecker::OnReport(
+    const cc::FrameSequenceMetrics::CustomReportData&) {
+  reported_ = true;
+  if (fail_if_reported_)
+    ADD_FAILURE() << "It should not be reported.";
+  test_base_->QuitRunLoop();
+}
+
+}  // namespace ui

ui/compositor/test/throughput_report_checker.h

+// Copyright 2020 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.
+
+#ifndef UI_COMPOSITOR_TEST_THROUGHPUT_REPORT_CHECKER_H_
+#define UI_COMPOSITOR_TEST_THROUGHPUT_REPORT_CHECKER_H_
+
+#include <memory>
+
+#include "base/bind.h"
+#include "cc/metrics/frame_sequence_metrics.h"
+
+namespace ui {
+class AnimationThroughputReporterTestBase;
+
+class ThroughputReportChecker {
+ public:
+  using ReportRepeatingCallback = base::RepeatingCallback<void(
+      const cc::FrameSequenceMetrics::CustomReportData&)>;
+  using ReportOnceCallback = base::OnceCallback<void(
+      const cc::FrameSequenceMetrics::CustomReportData&)>;
+
+  explicit ThroughputReportChecker(
+      AnimationThroughputReporterTestBase* test_base,
+      bool fail_if_reported = false)
+      : test_base_(test_base), fail_if_reported_(fail_if_reported) {}
+  ThroughputReportChecker(const ThroughputReportChecker&) = delete;
+  ThroughputReportChecker& operator=(const ThroughputReportChecker&) = delete;
+  ~ThroughputReportChecker() = default;
+
+  bool reported() const { return reported_; }
+
+  void reset() { reported_ = false; }
+
+  ReportRepeatingCallback repeating_callback() {
+    return base::BindRepeating(&ThroughputReportChecker::OnReport,
+                               base::Unretained(this));
+  }
+  ReportOnceCallback once_callback() {
+    return base::BindOnce(&ThroughputReportChecker::OnReport,
+                          base::Unretained(this));
+  }
+
+  // It waits until reported up to 5 seconds timeout. Returns true if it's
+  // reported.
+  bool WaitUntilReported();
+
+ private:
+  void OnReport(const cc::FrameSequenceMetrics::CustomReportData&);
+
+  AnimationThroughputReporterTestBase* test_base_;
+  bool reported_ = false;
+  bool fail_if_reported_ = false;
+};
+
+}  // namespace ui
+
+#endif  // UI_COMPOSITOR_TEST_THROUGHPUT_REPORT_CHECKER_H_