Test run for https://codereview.chromium.org/2725993002/ with the timer intentionally broken.

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 2401 matching lines @@
 
 bool WebContentsImpl::IsOverridingUserAgent() {
   return GetController().GetVisibleEntry() &&
          GetController().GetVisibleEntry()->GetIsOverridingUserAgent();
 }
 
 bool WebContentsImpl::IsJavaScriptDialogShowing() const {
   return is_showing_javascript_dialog_;
 }
 
+bool WebContentsImpl::ShouldIgnoreUnresponsiveRenderer() {
+  // Ignore unresponsive renderers if the debugger is attached to them since the
+  // unresponsiveness might be a result of the renderer sitting on a breakpoint.
+  //
+  // TODO(pfeldman): Fix this to only return true if the renderer is *actually*
+  // sitting on a breakpoint. https://crbug.com/684202
+  return DevToolsAgentHost::IsDebuggerAttached(this);
+}
+
 AccessibilityMode WebContentsImpl::GetAccessibilityMode() const {
   return accessibility_mode_;
 }
 
 void WebContentsImpl::AccessibilityEventReceived(
     const std::vector<AXEventNotificationDetails>& details) {
   for (auto& observer : observers_)
     observer.AccessibilityEventReceived(details);
 }
 
@@ skipping 2402 matching lines @@
 void WebContentsImpl::RendererUnresponsive(
     RenderWidgetHostImpl* render_widget_host,
     RendererUnresponsiveType type) {
   for (auto& observer : observers_)
     observer.OnRendererUnresponsive(render_widget_host);
 
   // Don't show hung renderer dialog for a swapped out RVH.
   if (render_widget_host != GetRenderViewHost()->GetWidget())
     return;
 
-  RenderFrameHostImpl* rfhi =
-      static_cast<RenderFrameHostImpl*>(GetRenderViewHost()->GetMainFrame());
-
-  // Ignore renderer unresponsive event if debugger is attached to the tab
-  // since the event may be a result of the renderer sitting on a breakpoint.
-  // See http://crbug.com/65458
-  if (DevToolsAgentHost::IsDebuggerAttached(this))
+  if (ShouldIgnoreUnresponsiveRenderer())
     return;
 
   // Record histograms about the type of renderer hang.
   UMA_HISTOGRAM_ENUMERATION(
       "ChildProcess.HangRendererType", type,
       RendererUnresponsiveType::RENDERER_UNRESPONSIVE_MAX);
 
-  // We might have been waiting for both beforeunload and unload ACK.
-  // Check if tab is to be unloaded first.
-  if (rfhi->IsWaitingForUnloadACK()) {
-    // Hang occurred while firing the unload handler.
-    // Pretend the handler fired so tab closing continues as if it had.
-    GetRenderViewHost()->set_sudden_termination_allowed(true);
-
-    if (!GetRenderManager()->ShouldCloseTabOnUnresponsiveRenderer())
-      return;
-
-    // If the tab hangs in the unload handler there's really nothing we can do
-    // to recover. Pretend the unload listeners have all fired and close
-    // the tab.
-    Close();
-    return;
-  }
-
+  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;
@@ skipping 546 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