Attempt at fixing possible shutdown crash

chrome/browser/ui/views/frame/browser_frame_ash.cc

 // Copyright 2013 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 "chrome/browser/ui/views/frame/browser_frame_ash.h"
 
 #include "ash/wm/window_state.h"
 #include "ash/wm/window_state_delegate.h"
 #include "ash/wm/window_util.h"
 #include "chrome/browser/ui/browser_commands.h"
 #include "chrome/browser/ui/browser_finder.h"
+#include "chrome/browser/ui/views/frame/browser_shutdown.h"
 #include "chrome/browser/ui/views/frame/browser_view.h"
 #include "ui/aura/client/aura_constants.h"
 #include "ui/aura/window.h"
 #include "ui/aura/window_observer.h"
 #include "ui/views/view.h"
 
 using aura::Window;
 
 namespace {
 
@@ skipping 59 matching lines @@
   // For legacy reasons v1 apps (like Secure Shell) are allowed to consume keys
   // like brightness, volume, etc. Otherwise these keys are handled by the
   // Ash window manager.
   window_state->set_can_consume_system_keys(browser->is_app());
 #endif  // defined(OS_CHROMEOS)
 }
 
 ///////////////////////////////////////////////////////////////////////////////
 // BrowserFrameAsh, views::NativeWidgetAura overrides:
 
+void BrowserFrameAsh::OnWindowDestroying() {
+  // Destroy any remaining WebContents early on. Doing so may result in
+  // calling back to one of the Views/LayoutManagers or supporting classes of
+  // BrowserView. By destroying here we ensure all said classes are valid.
+  DestroyBrowserWebContents(browser_view_->browser());
+  NativeWidgetAura::OnWindowDestroying();
+}
+
 void BrowserFrameAsh::OnWindowTargetVisibilityChanged(bool visible) {
   if (visible) {
     // Once the window has been shown we know the requested bounds
     // (if provided) have been honored and we can switch on window management.
     SetWindowAutoManaged();
   }
   views::NativeWidgetAura::OnWindowTargetVisibilityChanged(visible);
 }
 
 ////////////////////////////////////////////////////////////////////////////////
@@ skipping 21 matching lines @@
 ///////////////////////////////////////////////////////////////////////////////
 // BrowserFrameAsh, private:
 
 void BrowserFrameAsh::SetWindowAutoManaged() {
   if (browser_view_->browser()->type() != Browser::TYPE_POPUP ||
       browser_view_->browser()->is_app()) {
     ash::wm::GetWindowState(GetNativeWindow())->
         set_window_position_managed(true);
   }
 }