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

third_party/WebKit/Source/platform/scheduler/renderer/renderer_scheduler_impl.h

Index: third_party/WebKit/Source/platform/scheduler/renderer/renderer_scheduler_impl.h
diff --git a/third_party/WebKit/Source/platform/scheduler/renderer/renderer_scheduler_impl.h b/third_party/WebKit/Source/platform/scheduler/renderer/renderer_scheduler_impl.h
index 66cdc886167e622381ad39b1fad9a09e65dfa85c..47ad9d5d75303b369fe27f4617274d7d576af3c3 100644
--- a/third_party/WebKit/Source/platform/scheduler/renderer/renderer_scheduler_impl.h
+++ b/third_party/WebKit/Source/platform/scheduler/renderer/renderer_scheduler_impl.h
@@ -8,6 +8,7 @@
 #include "base/atomicops.h"
 #include "base/macros.h"
 #include "base/synchronization/lock.h"
+#include "device/base/synchronization/shared_memory_seqlock_buffer.h"
 #include "platform/scheduler/base/pollable_thread_safe_flag.h"
 #include "platform/scheduler/base/queueing_time_estimator.h"
 #include "platform/scheduler/base/thread_load_tracker.h"
@@ -122,6 +123,7 @@ class BLINK_PLATFORM_EXPORT RendererSchedulerImpl
   void SetTopLevelBlameContext(
       base::trace_event::BlameContext* blame_context) override;
   void SetRAILModeObserver(RAILModeObserver* observer) override;
+  bool ShouldForceEventsNonBlockingForUnresponsiveMainThread() const override;
 
   // RenderWidgetSignals::Observer implementation:
   void SetAllRenderWidgetsHidden(bool hidden) override;
@@ -134,9 +136,10 @@ class BLINK_PLATFORM_EXPORT RendererSchedulerImpl
                                    const base::PendingTask& task) override;
 
   // TaskTimeObserver implementation:
-  void ReportTaskTime(TaskQueue* task_queue,
-                      double start_time,
-                      double end_time) override;
+  void ReportTaskStartTime(double start_time) override;
+  void ReportTaskEndTime(TaskQueue* task_queue,
+                         double start_time,
+                         double end_time) override;
 
   // QueueingTimeEstimator::Client implementation:
   void OnQueueingTimeForWindowEstimated(base::TimeDelta queueing_time) override;
@@ -368,6 +371,11 @@ class BLINK_PLATFORM_EXPORT RendererSchedulerImpl
   CancelableClosureHolder end_renderer_hidden_idle_period_closure_;
   CancelableClosureHolder suspend_timers_when_backgrounded_closure_;
 
+  using SeqLockQueueingTimeEstimator =
+      device::SharedMemorySeqLockBuffer<QueueingTimeEstimator>;
+
+  SeqLockQueueingTimeEstimator seqlock_queueing_time_estimator_;
+
   // We have decided to improve thread safety at the cost of some boilerplate
   // (the accessors) for the following data members.
 
@@ -380,7 +388,7 @@ class BLINK_PLATFORM_EXPORT RendererSchedulerImpl
 
     TaskCostEstimator loading_task_cost_estimator;
     TaskCostEstimator timer_task_cost_estimator;
-    QueueingTimeEstimator queueing_time_estimator;
+    //    QueueingTimeEstimator queueing_time_estimator; // TODO
     IdleTimeEstimator idle_time_estimator;
     ThreadLoadTracker background_main_thread_load_tracker;
     ThreadLoadTracker foreground_main_thread_load_tracker;
@@ -388,6 +396,7 @@ class BLINK_PLATFORM_EXPORT RendererSchedulerImpl
     Policy current_policy;
     base::TimeTicks current_policy_expiration_time;
     base::TimeTicks estimated_next_frame_begin;
+    base::TimeTicks current_task_start_time;
     base::TimeDelta compositor_frame_interval;
     base::TimeDelta longest_jank_free_task_duration;
     int timer_queue_suspend_count;  // TIMER_TASK_QUEUE suspended if non-zero.
@@ -414,7 +423,7 @@ class BLINK_PLATFORM_EXPORT RendererSchedulerImpl
   };
 
   struct AnyThread {
-    AnyThread();
+    AnyThread(RendererSchedulerImpl* renderer_scheduler_impl);
     ~AnyThread();
 
     base::TimeTicks last_idle_period_end_time;