Check if the focused view is valid

ui/views/focus/focus_manager.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 "ui/views/focus/focus_manager.h"
 
 #include <algorithm>
 #include <vector>
 
 #include "base/auto_reset.h"
@@ skipping 283 matching lines @@
   keyboard_accessible_ = keyboard_accessible;
   // Disabling keyboard accessibility may cause the focused view to become not
   // focusable. Hence advance focus if necessary.
   AdvanceFocusIfNecessary();
 }
 
 void FocusManager::SetFocusedViewWithReason(
     View* view, FocusChangeReason reason) {
   if (focused_view_ == view)
     return;
+  // TODO(oshima|achuith): This is to diagnose crbug.com/687232.
+  // Change this to DCHECK once it's resolved.
+  CHECK(!view || ContainsView(view));
 
 #if !defined(OS_MACOSX)
   // TODO(warx): There are some AccessiblePaneViewTest failed on macosx.
   // crbug.com/650859. Remove !defined(OS_MACOSX) once that is fixed.
   //
   // If the widget isn't active store the focused view and then attempt to
   // activate the widget. If activation succeeds |view| will be focused.
   // If activation fails |view| will be focused the next time the widget is
   // made active.
   if (view && !widget_->IsActive()) {
@@ skipping 242 matching lines @@
 // |keyboard_accessible_| is only used on Mac.
 #if defined(OS_MACOSX)
   return keyboard_accessible_ ? view->IsAccessibilityFocusable()
                               : view->IsFocusable();
 #else
   return view->IsAccessibilityFocusable();
 #endif
 }
 
 }  // namespace views