Attempt 2 at: Fixes crash that occured because NativeViewHostAura::Detach was not

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 "base/bind.h"
 #include "base/bind_helpers.h"
 #include "base/command_line.h"
 #include "base/debug/trace_event.h"
@@ skipping 320 matching lines @@
   NOTIMPLEMENTED();
   return static_cast<gfx::NativeViewAccessible>(NULL);
 }
 
 void RenderWidgetHostViewAura::MovePluginWindows(
     const std::vector<webkit::npapi::WebPluginGeometry>& moves) {
   // We don't support windowed plugins.
 }
 
 void RenderWidgetHostViewAura::Focus() {
-  window_->Focus();
+  // Make sure we have a FocusManager before attempting to Focus(). In some
+  // situations we may not yet be in a valid Window hierarchy (such as reloading
+  // after out of memory discared the tab).
+  if (window_->GetFocusManager())
+    window_->Focus();
 }
 
 void RenderWidgetHostViewAura::Blur() {
   window_->Blur();
 }
 
 bool RenderWidgetHostViewAura::HasFocus() const {
   return window_->HasFocus();
 }
 
@@ skipping 1299 matching lines @@
     RenderWidgetHost* widget) {
   return new RenderWidgetHostViewAura(widget);
 }
 
 // static
 void RenderWidgetHostViewPort::GetDefaultScreenInfo(WebScreenInfo* results) {
   GetScreenInfoForWindow(results, NULL);
 }
 
 }  // namespace content