Port more focus controller unit tests and fix our focus rules.

services/window_manager/focus_rules.h

 // Copyright 2014 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.
 
 #ifndef SERVICES_WINDOW_MANAGER_FOCUS_RULES_H_
 #define SERVICES_WINDOW_MANAGER_FOCUS_RULES_H_
 
 #include "mojo/services/public/cpp/view_manager/types.h"
 #include "mojo/services/public/cpp/view_manager/view.h"
 
 namespace mojo {
 
 // Implemented by an object that establishes the rules about what can be
 // focused or activated.
 class FocusRules {
  public:
   virtual ~FocusRules() {}
 
+  // Returns true if the children of |window| can be activated.
+  virtual bool SupportsChildActivation(View* window) const = 0;
+
   // Returns true if |view| is a toplevel view. Whether or not a view
   // is considered toplevel is determined by a similar set of rules that
   // govern activation and focus. Not all toplevel views are activatable,
   // call CanActivateView() to determine if a view can be activated.
   virtual bool IsToplevelView(View* view) const = 0;
   // Returns true if |view| can be activated or focused.
   virtual bool CanActivateView(View* view) const = 0;
   // For CanFocusView(), null is supported, because null is a valid focusable
   // view (in the case of clearing focus).
   virtual bool CanFocusView(View* view) const = 0;
@@ skipping 24 matching lines @@
   //   RootView.
   // - it is being destroyed.
   // - it is being explicitly deactivated.
   // |ignore| cannot be null.
   virtual View* GetNextActivatableView(View* ignore) const = 0;
 };
 
 }  // namespace mojo
 
 #endif  // SERVICES_WINDOW_MANAGER_FOCUS_RULES_H_