Fix crash on clicking on <select> tag

content/browser/renderer_host/render_widget_host_view_aura.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/renderer_host/render_widget_host_view_aura.h"
 
 #include <set>
 #include <utility>
 
 #include "base/auto_reset.h"
@@ skipping 2442 matching lines @@
     cursor = ui::kCursorPointer;
 
   aura::client::CursorClient* cursor_client =
       aura::client::GetCursorClient(root_window);
   if (cursor_client) {
     cursor_client->SetCursor(cursor);
   }
 }
 
 ui::InputMethod* RenderWidgetHostViewAura::GetInputMethod() const {
+  if (!window_)
+    return nullptr;
   aura::Window* root_window = window_->GetRootWindow();
   if (!root_window)
-    return NULL;
+    return nullptr;
   return root_window->GetHost()->GetInputMethod();
 }
 
 void RenderWidgetHostViewAura::Shutdown() {
   if (!in_shutdown_) {
     in_shutdown_ = true;
     host_->ShutdownAndDestroyWidget(true);
   }
 }
 
@@ skipping 529 matching lines @@
 
 ////////////////////////////////////////////////////////////////////////////////
 // RenderWidgetHostViewBase, public:
 
 // static
 void RenderWidgetHostViewBase::GetDefaultScreenInfo(WebScreenInfo* results) {
   GetScreenInfoForWindow(results, NULL);
 }
 
 }  // namespace content