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

services/window_manager/basic_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_BASIC_FOCUS_RULES_H_
 #define SERVICES_WINDOW_MANAGER_BASIC_FOCUS_RULES_H_
 
 #include "services/window_manager/focus_rules.h"
 
 namespace mojo {
 
 class View;
 
 // The focusing rules used inside a window manager.
 //
 // This is intended to be a user supplyable, subclassable component passed to
 // WindowManagerApp, allowing for the creation of other window managers.
-//
-// TODO(erg): This was a straight move of the minimal focus rules from when
-// WindowManagerApp directly used the wm::FocusController. This implementation
-// is very incomplete. crbug.com/431047
 class BasicFocusRules : public FocusRules {
  public:
   BasicFocusRules(mojo::View* window_container);
   ~BasicFocusRules() override;
 
  protected:
   // Overridden from mojo::FocusRules:
+  bool SupportsChildActivation(mojo::View* view) const override;
   bool IsToplevelView(mojo::View* view) const override;
   bool CanActivateView(mojo::View* view) const override;
   bool CanFocusView(mojo::View* view) const override;
   mojo::View* GetToplevelView(mojo::View* view) const override;
   mojo::View* GetActivatableView(mojo::View* view) const override;
   mojo::View* GetFocusableView(mojo::View* view) const override;
   mojo::View* GetNextActivatableView(mojo::View* activatable) const override;
 
  private:
+  bool CanFocusViewImpl(View* view) const;
+
+  // Tests to see if |view| is in |window_container_|.
+  bool IsViewParentedToWindowContainer(View* view) const;
+
   mojo::View* window_container_;
 
   DISALLOW_COPY_AND_ASSIGN(BasicFocusRules);
 };
 
 }  // namespace mojo
 
 #endif  // SERVICES_WINDOW_MANAGER_BASIC_FOCUS_RULES_H_