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

third_party/WebKit/Source/platform/scheduler/base/test_task_time_observer.h

Index: third_party/WebKit/Source/platform/scheduler/base/test_task_time_observer.h
diff --git a/third_party/WebKit/Source/platform/scheduler/base/test_task_time_observer.h b/third_party/WebKit/Source/platform/scheduler/base/test_task_time_observer.h
index 7d2e64dccb08a83b39dc79d178f526921a6585e2..2800f1a413248fb789d1e26f0a8f2bdcd3947bfe 100644
--- a/third_party/WebKit/Source/platform/scheduler/base/test_task_time_observer.h
+++ b/third_party/WebKit/Source/platform/scheduler/base/test_task_time_observer.h
@@ -13,9 +13,22 @@ namespace scheduler {
 
 class TestTaskTimeObserver : public TaskTimeObserver {
  public:
-  void ReportTaskTime(TaskQueue* task_queue,
-                      double start_time,
-                      double end_time) override {}
+  void ReportTaskStartTime(double start_time) override {
+    task_start_times_.push_back(start_time);
+  }
+
+  void ReportTaskEndTime(TaskQueue* task_queue,
+                         double start_time,
+                         double end_time) override {
+    task_end_times_.push_back(end_time);
+  }
+
+  std::vector<double> task_start_times() { return task_start_times_; }
+  std::vector<double> task_end_times() { return task_end_times_; }
+
+ private:
+  std::vector<double> task_start_times_;
+  std::vector<double> task_end_times_;
 };
 
 }  // namespace scheduler