Give up focus if the focused view becomes unfocusable

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 339 matching lines @@
 
 void FocusManager::ClearFocus() {
   // SetFocusedView(NULL) is going to clear out the stored view to. We need to
   // persist it in this case.
   views::View* focused_view = GetStoredFocusView();
   SetFocusedView(NULL);
   ClearNativeFocus();
   SetStoredFocusView(focused_view);
 }
 
+void FocusManager::AdvanceFocusIfNecessary() {
+  // If widget is inactive, there is no focused view to check. The stored view
+  // will also be checked for focusability when it is being restored.
+  if (!widget_->IsActive())
+    return;
+
+  // If widget is active and focused view is not focusable, advance focus or,
+  // if not possible, clear focus.
+  if (focused_view_ && !focused_view_->IsAccessibilityFocusable()) {
+    AdvanceFocus(false);
+    if (focused_view_ && !focused_view_->IsAccessibilityFocusable())
+      ClearFocus();
+  }
+}
+
 void FocusManager::StoreFocusedView(bool clear_native_focus) {
   View* focused_view = focused_view_;
   // Don't do anything if no focused view. Storing the view (which is NULL), in
   // this case, would clobber the view that was previously saved.
   if (!focused_view_)
     return;
 
   View* v = focused_view_;
 
   if (clear_native_focus) {
@@ skipping 215 matching lines @@
   }
   if (key_code == ui::VKEY_RIGHT || key_code == ui::VKEY_DOWN) {
     AdvanceFocus(false);
     return true;
   }
 
   return false;
 }
 
 }  // namespace views