Move beforeunload hang timer duties to its own timer.

content/browser/frame_host/render_frame_host_impl.cc

Index: content/browser/frame_host/render_frame_host_impl.cc
diff --git a/content/browser/frame_host/render_frame_host_impl.cc b/content/browser/frame_host/render_frame_host_impl.cc
index ff676db56414b28a6a8986670d5def976e6e88b8..b802e463954c6addd214e1f540079774f5ff6cb2 100644
--- a/content/browser/frame_host/render_frame_host_impl.cc
+++ b/content/browser/frame_host/render_frame_host_impl.cc
@@ -369,6 +369,9 @@ RenderFrameHostImpl::RenderFrameHostImpl(SiteInstance* site_instance,
   SetUpMojoIfNeeded();
   swapout_event_monitor_timeout_.reset(new TimeoutMonitor(base::Bind(
       &RenderFrameHostImpl::OnSwappedOut, weak_ptr_factory_.GetWeakPtr())));
+  beforeunload_timeout_.reset(
+      new TimeoutMonitor(base::Bind(&RenderFrameHostImpl::BeforeUnloadTimeout,
+                                    weak_ptr_factory_.GetWeakPtr())));
 
   if (widget_routing_id != MSG_ROUTING_NONE) {
     // TODO(avi): Once RenderViewHostImpl has-a RenderWidgetHostImpl, the main
@@ -1469,8 +1472,7 @@ void RenderFrameHostImpl::OnBeforeUnloadACK(
   }
   // Resets beforeunload waiting state.
   is_waiting_for_beforeunload_ack_ = false;
-  render_view_host_->GetWidget()->decrement_in_flight_event_count();
-  render_view_host_->GetWidget()->StopHangMonitorTimeout();
+  beforeunload_timeout_->Stop();
   send_before_unload_start_time_ = base::TimeTicks();
 
   // PlzNavigate: if the ACK is for a navigation, send it to the Navigator to
@@ -1692,6 +1694,7 @@ void RenderFrameHostImpl::OnRunBeforeUnloadConfirm(
   // shouldn't process input events.
   GetProcess()->SetIgnoreInputEvents(true);
   render_view_host_->GetWidget()->StopHangMonitorTimeout();
+  beforeunload_timeout_->Stop();
   delegate_->RunBeforeUnloadConfirm(this, is_reload, reply_msg);
 }
 
@@ -2392,8 +2395,7 @@ void RenderFrameHostImpl::ResetWaitingState() {
   // navigations to be ignored in OnDidCommitProvisionalLoad.
   if (is_waiting_for_beforeunload_ack_) {
     is_waiting_for_beforeunload_ack_ = false;
-    render_view_host_->GetWidget()->decrement_in_flight_event_count();
-    render_view_host_->GetWidget()->StopHangMonitorTimeout();
+    beforeunload_timeout_->Stop();
   }
   send_before_unload_start_time_ = base::TimeTicks();
   render_view_host_->is_waiting_for_close_ack_ = false;
@@ -2538,13 +2540,10 @@ void RenderFrameHostImpl::DispatchBeforeUnload(bool for_navigation,
       // reply from the dialog.
       SimulateBeforeUnloadAck();
     } else {
-      // Increment the in-flight event count, to ensure that input events won't
-      // cancel the timeout timer.
-      render_view_host_->GetWidget()->increment_in_flight_event_count();
-      render_view_host_->GetWidget()->StartHangMonitorTimeout(
-          TimeDelta::FromMilliseconds(RenderViewHostImpl::kUnloadTimeoutMS),
-          blink::WebInputEvent::Undefined,
-          RendererUnresponsiveType::RENDERER_UNRESPONSIVE_BEFORE_UNLOAD);
+      beforeunload_timeout_type_ =
+          RendererUnresponsiveType::RENDERER_UNRESPONSIVE_BEFORE_UNLOAD;
+      beforeunload_timeout_->Start(
+          TimeDelta::FromMilliseconds(RenderViewHostImpl::kUnloadTimeoutMS));
       send_before_unload_start_time_ = base::TimeTicks::Now();
       Send(new FrameMsg_BeforeUnload(routing_id_, is_reload));
     }
@@ -2613,33 +2612,30 @@ void RenderFrameHostImpl::JavaScriptDialogClosed(
     bool dialog_was_suppressed) {
   GetProcess()->SetIgnoreInputEvents(false);
 
-  // If we are executing as part of beforeunload event handling, we don't
-  // want to use the regular hung_renderer_delay_ms_ if the user has agreed to
-  // leave the current page. In this case, use the regular timeout value used
-  // during the beforeunload handling.
+  // If executing as part of beforeunload event handling, resume the timeout
+  // that was suspended when the dialog was shown in OnRunBeforeUnloadConfirm().
   if (is_before_unload_dialog) {
-    RendererUnresponsiveType type =
+    beforeunload_timeout_type_ =
         success ? RendererUnresponsiveType::RENDERER_UNRESPONSIVE_BEFORE_UNLOAD
                 : RendererUnresponsiveType::RENDERER_UNRESPONSIVE_DIALOG_CLOSED;
-    render_view_host_->GetWidget()->StartHangMonitorTimeout(
-        success
-            ? TimeDelta::FromMilliseconds(RenderViewHostImpl::kUnloadTimeoutMS)
-            : render_view_host_->GetWidget()->hung_renderer_delay(),
-        blink::WebInputEvent::Undefined, type);
+    beforeunload_timeout_->Start(
+        TimeDelta::FromMilliseconds(RenderViewHostImpl::kUnloadTimeoutMS));
   }
 
   SendJavaScriptDialogReply(reply_msg, success, user_input);
 
   // If we are waiting for a beforeunload ack and the user has suppressed
-  // messages, kill the tab immediately; a page that's spamming alerts in
-  // onbeforeunload is presumably malicious, so there's no point in continuing
-  // to run its script and dragging out the process. This must be done after
-  // sending the reply since RenderView can't close correctly while waiting for
-  // a response.
+  // messages, kill the tab immediately. A page that's spamming is presumably
+  // malicious, so there's no point in continuing to run its script and dragging
+  // out the process. This must be done after sending the reply since RenderView
+  // can't close correctly while waiting for a response.
   if (is_before_unload_dialog && dialog_was_suppressed) {
-    render_view_host_->GetWidget()->delegate()->RendererUnresponsive(
-        render_view_host_->GetWidget(),
-        RendererUnresponsiveType::RENDERER_UNRESPONSIVE_DIALOG_SUPPRESSED);
+    UMA_HISTOGRAM_ENUMERATION(
+        "ChildProcess.HangRendererType",
+        RendererUnresponsiveType::RENDERER_UNRESPONSIVE_DIALOG_SUPPRESSED,
+        RendererUnresponsiveType::RENDERER_UNRESPONSIVE_MAX);
+
+    SimulateBeforeUnloadAck();
   }
 }
 
@@ -3464,4 +3460,15 @@ RenderFrameHostImpl::TakeNavigationHandleForCommit(
       entry_id_for_data_nav, false);  // started_from_context_menu
 }
 
+void RenderFrameHostImpl::BeforeUnloadTimeout() {
+  if (render_view_host_->GetDelegate()->ShouldIgnoreUnresponsiveRenderer())
+    return;
+
+  UMA_HISTOGRAM_ENUMERATION(
+      "ChildProcess.HangRendererType", beforeunload_timeout_type_,
+      RendererUnresponsiveType::RENDERER_UNRESPONSIVE_MAX);
+
+  SimulateBeforeUnloadAck();
+}
+
 }  // namespace content