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

third_party/WebKit/public/platform/scheduler/renderer/renderer_scheduler.h

 // Copyright 2014 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 THIRD_PARTY_WEBKIT_PUBLIC_PLATFORM_SCHEDULER_RENDERER_RENDERER_SCHEDULER_H_
 #define THIRD_PARTY_WEBKIT_PUBLIC_PLATFORM_SCHEDULER_RENDERER_RENDERER_SCHEDULER_H_
 
 #include <memory>
 
 #include "base/macros.h"
@@ skipping 168 matching lines @@
   virtual void SetTopLevelBlameContext(
       base::trace_event::BlameContext* blame_context) = 0;
 
   // The renderer scheduler maintains an estimated RAIL mode[1]. This observer
   // can be used to get notified when the mode changes. The observer will be
   // called on the main thread and must outlive this class.
   // [1]
   // https://developers.google.com/web/tools/chrome-devtools/profile/evaluate-performance/rail
   virtual void SetRAILModeObserver(RAILModeObserver* observer) = 0;
 
+  virtual bool ShouldForceEventsNonBlockingForUnresponsiveMainThread()

[Sami, 2016/11/02 19:01:42]

This probably deserves a doc comment here. I'd also suggest renaming this to
something like MainThreadSeemsUnresponsive() since we could potentially make
other decisions based on this too and the code in the scheduler doesn't really
care about non-blocking events per se.

[tdresser, 2016/11/03 13:56:10]

Done.

+      const = 0;
+
  protected:
   RendererScheduler();
   DISALLOW_COPY_AND_ASSIGN(RendererScheduler);
 };
 
 }  // namespace scheduler
 }  // namespace blink
 
 #endif  // THIRD_PARTY_WEBKIT_PUBLIC_PLATFORM_SCHEDULER_RENDERER_RENDERER_SCHEDULER_H_