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

content/browser/web_contents/web_contents_impl.cc

 // Copyright (c) 2012 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.
 
 #include "content/browser/web_contents/web_contents_impl.h"
 
 #include <stddef.h>
 
 #include <cmath>
 #include <utility>
@@ skipping 4840 matching lines @@
     return;
 
   if (ShouldIgnoreUnresponsiveRenderer())
     return;
 
   // Record histograms about the type of renderer hang.
   UMA_HISTOGRAM_ENUMERATION(
       "ChildProcess.HangRendererType", type,
       RendererUnresponsiveType::RENDERER_UNRESPONSIVE_MAX);
 
+  RenderFrameHostImpl* rfhi =
+      static_cast<RenderFrameHostImpl*>(GetRenderViewHost()->GetMainFrame());
+  if (rfhi->is_waiting_for_beforeunload_ack()) {
+    // If the hang is in the beforeunload handler, pretend the beforeunload
+    // listeners have all fired and allow the delegate to continue closing;
+    // the user will not have the option of cancelling the close.
+    rfhi->SimulateBeforeUnloadAck();
+    return;
+  }
+
   if (!GetRenderViewHost() || !GetRenderViewHost()->IsRenderViewLive())
     return;
 
   if (delegate_) {
     WebContentsUnresponsiveState unresponsive_state;
     unresponsive_state.reason = type;
     unresponsive_state.outstanding_ack_count =
         render_widget_host->in_flight_event_count();
     unresponsive_state.outstanding_event_type =
         render_widget_host->hang_monitor_event_type();
@@ skipping 538 matching lines @@
     RenderViewHost* render_view_host = RenderViewHost::From(render_widget_host);
     if (!render_view_host)
       continue;
     render_view_host_set.insert(render_view_host);
   }
   for (RenderViewHost* render_view_host : render_view_host_set)
     render_view_host->OnWebkitPreferencesChanged();
 }
 
 }  // namespace content