Force events to be non blocking if main thread is unresponsive.

third_party/WebKit/Source/platform/scheduler/renderer/renderer_scheduler_impl_unittest.cc

Index: third_party/WebKit/Source/platform/scheduler/renderer/renderer_scheduler_impl_unittest.cc
diff --git a/third_party/WebKit/Source/platform/scheduler/renderer/renderer_scheduler_impl_unittest.cc b/third_party/WebKit/Source/platform/scheduler/renderer/renderer_scheduler_impl_unittest.cc
index 4fa581f5499952eff36d87604c4f6e1f307a6577..5ff35653c524bba5079d146912e617af33952074 100644
--- a/third_party/WebKit/Source/platform/scheduler/renderer/renderer_scheduler_impl_unittest.cc
+++ b/third_party/WebKit/Source/platform/scheduler/renderer/renderer_scheduler_impl_unittest.cc
@@ -186,7 +186,10 @@ class RendererSchedulerImplForTest : public RendererSchedulerImpl {
 
   RendererSchedulerImplForTest(
       scoped_refptr<SchedulerTqmDelegate> main_task_runner)
-      : RendererSchedulerImpl(main_task_runner), update_policy_count_(0) {}
+      : RendererSchedulerImpl(main_task_runner), update_policy_count_(0) {
+    main_thread_responsiveness_threshold_ =
+        base::TimeDelta::FromMilliseconds(200);
+  }
 
   void UpdatePolicyLocked(UpdateType update_type) override {
     update_policy_count_++;
@@ -526,6 +529,23 @@ class RendererSchedulerImplTest : public testing::Test {
     return scheduler_->MainThreadOnly().navigation_task_expected_count;
   }
 
+  void AdvanceTimeWithTask(double duration) {
+    double start = (clock_->NowTicks() - base::TimeTicks()).InSecondsF();
+    clock_->Advance(base::TimeDelta::FromSecondsD(duration));
+    double end = (clock_->NowTicks() - base::TimeTicks()).InSecondsF();
+    scheduler_->ReportTaskStartTime(start);
+    scheduler_->ReportTaskEndTime(scheduler_->TimerTaskRunner().get(), start,
+                                  end);
+  }
+
+  void GetQueueingTimeEstimatorLock() {
+    scheduler_->seqlock_queueing_time_estimator_.seqlock.WriteBegin();
+  }
+
+  void DropQueueingTimeEstimatorLock() {
+    scheduler_->seqlock_queueing_time_estimator_.seqlock.WriteEnd();
+  }
+
   // Helper for posting several tasks of specific types. |task_descriptor| is a
   // string with space delimited task identifiers. The first letter of each
   // task identifier specifies the task type:
@@ -3482,5 +3502,45 @@ TEST_F(RendererSchedulerImplTest, EnableVirtualTime) {
             scheduler_->GetVirtualTimeDomain());
 }
 
+TEST_F(RendererSchedulerImplTest, UnresponsiveMainThread) {
+  EXPECT_FALSE(scheduler_->MainThreadSeemsUnresponsive());
+
+  // Add one second long task.
+  AdvanceTimeWithTask(1);
+  EXPECT_TRUE(scheduler_->MainThreadSeemsUnresponsive());
+
+  // Wait a second.
+  clock_->Advance(base::TimeDelta::FromSecondsD(2));
+
+  AdvanceTimeWithTask(0.5);
+  EXPECT_FALSE(scheduler_->MainThreadSeemsUnresponsive());
+}
+
+TEST_F(RendererSchedulerImplTest, ResponsiveMainThreadDuringTask) {
+  EXPECT_FALSE(scheduler_->MainThreadSeemsUnresponsive());
+  clock_->Advance(base::TimeDelta::FromSecondsD(2));
+  scheduler_->ReportTaskStartTime(
+      (clock_->NowTicks() - base::TimeTicks()).InSecondsF());
+  EXPECT_FALSE(scheduler_->MainThreadSeemsUnresponsive());
+}
+
+TEST_F(RendererSchedulerImplTest, UnresponsiveMainThreadWithContention) {
+  // Process a long task, lock the queueing time estimator, and check that we
+  // still report the main thread is unresponsive.
+  AdvanceTimeWithTask(1);
+  EXPECT_TRUE(scheduler_->MainThreadSeemsUnresponsive());
+  GetQueueingTimeEstimatorLock();
+  EXPECT_TRUE(scheduler_->MainThreadSeemsUnresponsive());
+
+  // Advance the clock, so that in the last second, we were responsive.
+  clock_->Advance(base::TimeDelta::FromSecondsD(2));
+  // While the queueing time estimator is locked, we believe the thread to still
+  // be unresponsive.
+  EXPECT_TRUE(scheduler_->MainThreadSeemsUnresponsive());
+  // Once we've dropped the lock, we realize the main thread is responsive.
+  DropQueueingTimeEstimatorLock();
+  EXPECT_FALSE(scheduler_->MainThreadSeemsUnresponsive());
+}
+
 }  // namespace scheduler
 }  // namespace blink