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content/browser/renderer_host/render_widget_host_impl.h

Index: content/browser/renderer_host/render_widget_host_impl.h
diff --git a/content/browser/renderer_host/render_widget_host_impl.h b/content/browser/renderer_host/render_widget_host_impl.h
index 4711fac648412dfaa494cf9bae36d80d09eef9c0..2a22893f9b676d880773f34be5bc5ab11c9ea31b 100644
--- a/content/browser/renderer_host/render_widget_host_impl.h
+++ b/content/browser/renderer_host/render_widget_host_impl.h
@@ -301,6 +301,10 @@ class CONTENT_EXPORT RenderWidgetHostImpl : public RenderWidgetHost,
   // responsive.
   void StopHangMonitorTimeout();
 
+  // Marks the renderer as being known-unresponsive, so that the hang monitor
+  // doesn't wait for responses.
+  void SetHangMonitorKnownUnresponsive(bool unresponsive);
+
   // Starts the rendering timeout, which will clear displayed graphics if
   // a new compositor frame is not received before it expires.
   void StartNewContentRenderingTimeout();
@@ -833,6 +837,9 @@ class CONTENT_EXPORT RenderWidgetHostImpl : public RenderWidgetHost,
   // This value indicates how long to wait before we consider a renderer hung.
   base::TimeDelta hung_renderer_delay_;
 
+  // This is the number of calls to SetHangMonitorKnownUnresponsive.
+  int known_unresponsive_renderer_count_ = 0;

[Charlie Reis, 2016/10/05 22:00:59]

When would this be more than one?

+
   // Stores the reason the hang_monitor_timeout_ has been started. Used to
   // report histograms if the renderer is hung.
   RenderWidgetHostDelegate::RendererUnresponsiveType hang_monitor_reason_;