Don't let Blink handle events if we're shuting down.

third_party/WebKit/Source/web/WebFrameWidgetImpl.cpp

 /*
  * Copyright (C) 2014 Google Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are
  * met:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
  *     * Redistributions in binary form must reproduce the above
@@ skipping 293 matching lines @@
     FrameView* view = m_localRoot->frameView();
 
     WebRect damagedRect(0, 0, m_size.width, m_size.height);
     view->invalidateRect(damagedRect);
 }
 
 const WebInputEvent* WebFrameWidgetImpl::m_currentInputEvent = nullptr;
 
 WebInputEventResult WebFrameWidgetImpl::handleInputEvent(const WebInputEvent& inputEvent)
 {
+    TRACE_EVENT1("input", "WebFrameWidgetImpl::handleInputEvent", "type", inputTypeToName(inputEvent.type));
 
-    TRACE_EVENT1("input", "WebFrameWidgetImpl::handleInputEvent", "type", inputTypeToName(inputEvent.type));
+    // Don't handle events once we've started shutting down.
+    if (!page())

[dtapuska, 2016/04/29 14:31:27]

Is it preferred to collapse this with the return below; like

if (!page() || m_ignoreInputEvents)

[bokan, 2016/04/29 14:49:00]

IMO, in this case, they're unrelated and it's more natural to comment the cases
if they're separate.

[dcheng, 2016/04/29 18:36:29]

Dumb question: how come we don't hit this in the WebViewImpl case?

+        return WebInputEventResult::NotHandled;
 
     // Report the event to be NOT processed by WebKit, so that the browser can handle it appropriately.
     if (m_ignoreInputEvents)
         return WebInputEventResult::NotHandled;
 
     // FIXME: pass event to m_localRoot's WebDevToolsAgentImpl once available.
 
     TemporaryChange<const WebInputEvent*> currentEventChange(m_currentInputEvent, &inputEvent);
 
     if (m_mouseCaptureNode && WebInputEvent::isMouseEventType(inputEvent.type)) {
@@ skipping 761 matching lines @@
 
 HitTestResult WebFrameWidgetImpl::hitTestResultForRootFramePos(const IntPoint& posInRootFrame)
 {
     IntPoint docPoint(m_localRoot->frame()->view()->rootFrameToContents(posInRootFrame));
     HitTestResult result = m_localRoot->frame()->eventHandler().hitTestResultAtPoint(docPoint, HitTestRequest::ReadOnly | HitTestRequest::Active);
     result.setToShadowHostIfInUserAgentShadowRoot();
     return result;
 }
 
 } // namespace blink