Null-check GetView before using it in GetFocusedRenderWidgetHost.

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 <utility>
 
 #include "base/command_line.h"
 #include "base/lazy_instance.h"
@@ skipping 1629 matching lines @@
 
   // Events for widgets other than the main frame (e.g., popup menus) should be
   // forwarded directly to the widget they arrived on.
   if (receiving_widget != GetMainFrame()->GetRenderWidgetHost())
     return receiving_widget;
 
   FrameTreeNode* focused_frame = frame_tree_.GetFocusedFrame();
   if (!focused_frame)
     return receiving_widget;
 
-  return RenderWidgetHostImpl::From(
-      focused_frame->current_frame_host()->GetView()->GetRenderWidgetHost());
+  // The view may be null if a subframe's renderer process has crashed while
+  // the subframe has focus.  Drop the event in that case.  Do not give
+  // it to the main frame, so that the user doesn't unexpectedly type into the
+  // wrong frame if a focused subframe renderer crashes while they type.
+  RenderWidgetHostView* view = focused_frame->current_frame_host()->GetView();
+  if (!view)
+    return nullptr;
+
+  return RenderWidgetHostImpl::From(view->GetRenderWidgetHost());
 }
 
 void WebContentsImpl::EnterFullscreenMode(const GURL& origin) {
   // This method is being called to enter renderer-initiated fullscreen mode.
   // Make sure any existing fullscreen widget is shut down first.
   RenderWidgetHostView* const widget_view = GetFullscreenRenderWidgetHostView();
   if (widget_view)
     RenderWidgetHostImpl::From(widget_view->GetRenderWidgetHost())->Shutdown();
 
   if (delegate_)
@@ skipping 3144 matching lines @@
   return NULL;
 }
 
 void WebContentsImpl::SetForceDisableOverscrollContent(bool force_disable) {
   force_disable_overscroll_content_ = force_disable;
   if (view_)
     view_->SetOverscrollControllerEnabled(CanOverscrollContent());
 }
 
 }  // namespace content