Revert of Move beforeunload hang timer duties to its own timer.

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 e04e58a2beb118d80ebc066f66073d1e06c19add..b6aa99ec6f3c4147adec40a795432f45b41385ef 100644
--- a/content/browser/renderer_host/render_widget_host_impl.h
+++ b/content/browser/renderer_host/render_widget_host_impl.h
@@ -546,6 +546,14 @@
                         uint32_t offset,
                         const gfx::Range& range);
 
+  // Expose increment/decrement of the in-flight event count, so
+  // RenderViewHostImpl can account for in-flight beforeunload/unload events.
+  int increment_in_flight_event_count() { return ++in_flight_event_count_; }
+  int decrement_in_flight_event_count() {
+    DCHECK_GT(in_flight_event_count_, 0);
+    return --in_flight_event_count_;
+  }
+
   size_t in_flight_event_count() const { return in_flight_event_count_; }
   blink::WebInputEvent::Type hang_monitor_event_type() const {
     return hang_monitor_event_type_;