Attempt to re-land FocusManager removal from Aura.

ui/aura/root_window.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/aura/root_window.h"
 
 #include <vector>
 
 #include "base/bind.h"
 #include "base/command_line.h"
 #include "base/debug/trace_event.h"
 #include "base/logging.h"
 #include "base/message_loop/message_loop.h"
-#include "ui/aura/client/activation_client.h"
 #include "ui/aura/client/capture_client.h"
 #include "ui/aura/client/cursor_client.h"
 #include "ui/aura/client/event_client.h"
 #include "ui/aura/client/focus_client.h"
 #include "ui/aura/client/screen_position_client.h"
 #include "ui/aura/env.h"
 #include "ui/aura/root_window_host.h"
 #include "ui/aura/root_window_observer.h"
 #include "ui/aura/root_window_transformer.h"
 #include "ui/aura/window.h"
@@ skipping 674 matching lines @@
   DispatchMouseExitToHidingWindow(detached);
   OnWindowHidden(detached, new_root ? WINDOW_MOVING : WINDOW_HIDDEN);
 
   if (detached->IsVisible() &&
       detached->ContainsPointInRoot(GetLastMouseLocationInRoot())) {
     PostMouseMoveEventAfterWindowChange();
   }
 }
 
 void RootWindow::OnWindowHidden(Window* invisible, WindowHiddenReason reason) {
-  // TODO(beng): This should be removed once FocusController is turned on.
-  if (client::GetFocusClient(this)) {
-    client::GetFocusClient(this)->OnWindowHiddenInRootWindow(
-        invisible, this, reason == WINDOW_DESTROYED);
-  }
-
   // Do not clear the capture, and the |event_dispatch_target_| if the
   // window is moving across root windows, because the target itself
   // is actually still visible and clearing them stops further event
   // processing, which can cause unexpected behaviors. See
   // crbug.com/157583
   if (reason != WINDOW_MOVING) {
     Window* capture_window = aura::client::GetCaptureWindow(this);
     // If the ancestor of the capture window is hidden,
     // release the capture.
     if (invisible->Contains(capture_window) && invisible != this)
@@ skipping 453 matching lines @@
 }
 
 gfx::Transform RootWindow::GetInverseRootTransform() const {
   float scale = ui::GetDeviceScaleFactor(layer());
   gfx::Transform transform;
   transform.Scale(1.0f / scale, 1.0f / scale);
   return transformer_->GetInverseTransform() * transform;
 }
 
 }  // namespace aura