Hook up the FocusController behind a flag.

ui/views/corewm/focus_controller.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/corewm/focus_controller.h"
 
 #include "base/auto_reset.h"
 #include "ui/aura/client/aura_constants.h"
 #include "ui/aura/env.h"
 #include "ui/views/corewm/focus_change_event.h"
@@ skipping 27 matching lines @@
                                   ui::EventTarget** event_dispatch_target) {
   int result = ui::ER_UNHANDLED;
   {
     base::AutoReset<ui::EventTarget*> reset(event_dispatch_target, *state);
     FocusChangeEvent changing_event(changing_event_type);
     result = dispatcher->ProcessEvent(*state, &changing_event);
   }
   DCHECK(!(result & ui::ER_CONSUMED))
       << "Focus and Activation events cannot be consumed";
 
+  aura::Window* lost_active = *state;
   *state = new_state;
 
   if (restack && new_state) {
     StackTransientParentsBelowModalWindow(new_state);
     new_state->parent()->StackChildAtTop(new_state);
   }
 
   {
     base::AutoReset<ui::EventTarget*> reset(event_dispatch_target, *state);
     FocusChangeEvent changed_event(changed_event_type);
+    FocusChangeEvent::DispatcherApi(&changed_event).set_last_focus(lost_active);
     dispatcher->ProcessEvent(*state, &changed_event);
   }
 }
 
 }  // namespace
 
 ////////////////////////////////////////////////////////////////////////////////
 // FocusController, public:
 
 FocusController::FocusController(FocusRules* rules)
     : active_window_(NULL),
       focused_window_(NULL),
       event_dispatch_target_(NULL),
       rules_(rules) {
   DCHECK(rules);
   FocusChangeEvent::RegisterEventTypes();
   aura::Env::GetInstance()->AddObserver(this);
 }
 
 FocusController::~FocusController() {
   aura::Env::GetInstance()->RemoveObserver(this);
 }
 
-void FocusController::FocusWindow(aura::Window* window) {
-  // Focusing a window also activates its containing activatable window. Note
-  // that the rules could redirect activation activation and/or focus.
-  aura::Window* focusable = rules_->GetFocusableWindow(window);
-  SetActiveWindow(rules_->GetActivatableWindow(focusable));
-  DCHECK(GetActiveWindow()->Contains(focusable));
-  SetFocusedWindow(focusable);
-}
-
 ////////////////////////////////////////////////////////////////////////////////
 // FocusController, aura::client::ActivationClient implementation:
 
 void FocusController::AddObserver(
     aura::client::ActivationChangeObserver* observer) {
-  NOTREACHED();
+  //NOTREACHED();
 }
 
 void FocusController::RemoveObserver(
     aura::client::ActivationChangeObserver* observer) {
-  NOTREACHED();
+  //NOTREACHED();
 }
 
 void FocusController::ActivateWindow(aura::Window* window) {
-  FocusWindow(window);
+  FocusWindow(window, NULL);
 }
 
 void FocusController::DeactivateWindow(aura::Window* window) {
-  FocusWindow(rules_->GetNextActivatableWindow(window));
+  FocusWindow(rules_->GetNextActivatableWindow(window), NULL);
 }
 
 aura::Window* FocusController::GetActiveWindow() {
   return active_window_;
 }
 
 aura::Window* FocusController::GetActivatableWindow(aura::Window* window) {
   return rules_->GetActivatableWindow(window);
 }
 
 bool FocusController::OnWillFocusWindow(aura::Window* window,
                                         const ui::Event* event) {
   NOTREACHED();
   return false;
 }
 
 bool FocusController::CanActivateWindow(aura::Window* window) const {
   return rules_->CanActivateWindow(window);
 }
 
 ////////////////////////////////////////////////////////////////////////////////
+// FocusController, aura::client::FocusClient implementation:
+
+void FocusController::AddObserver(
+    aura::client::FocusChangeObserver* observer) {
+  //NOTREACHED();
+}
+
+void FocusController::RemoveObserver(
+    aura::client::FocusChangeObserver* observer) {
+  //NOTREACHED();
+}
+
+void FocusController::FocusWindow(aura::Window* window,
+                                  const ui::Event* event) {
+  // Focusing a window also activates its containing activatable window. Note
+  // that the rules could redirect activation activation and/or focus.
+  aura::Window* focusable = rules_->GetFocusableWindow(window);
+  SetActiveWindow(rules_->GetActivatableWindow(focusable));
+  DCHECK(GetActiveWindow()->Contains(focusable));
+  SetFocusedWindow(focusable);
+}
+
+aura::Window* FocusController::GetFocusedWindow() {
+  return focused_window_;
+}
+
+////////////////////////////////////////////////////////////////////////////////
 // FocusController, ui::EventHandler implementation:
 ui::EventResult FocusController::OnKeyEvent(ui::KeyEvent* event) {
   return ui::ER_UNHANDLED;
 }
 
 ui::EventResult FocusController::OnMouseEvent(ui::MouseEvent* event) {
   if (event->type() == ui::ET_MOUSE_PRESSED)
     WindowFocusedFromInputEvent(static_cast<aura::Window*>(event->target()));
   return ui::ER_UNHANDLED;
 }
@@ skipping 95 matching lines @@
     aura::Window* next_activatable = rules_->GetNextActivatableWindow(window);
     SetActiveWindow(next_activatable);
     SetFocusedWindow(next_activatable);
   } else if (window->Contains(focused_window_)) {
     // Active window isn't changing, but focused window might be.
     SetFocusedWindow(rules_->GetNextFocusableWindow(window));
   }
 }
 
 void FocusController::WindowFocusedFromInputEvent(aura::Window* window) {
-  FocusWindow(window);
+  FocusWindow(window, NULL);
 }
 
 }  // namespace corewm
 }  // namespace views