Attempt to re-land FocusManager removal from Aura.

ui/aura/focus_manager.cc

Index: ui/aura/focus_manager.cc
diff --git a/ui/aura/focus_manager.cc b/ui/aura/focus_manager.cc
deleted file mode 100644
index 921406b4c762e3ef0ed9514f7e0c440dc0f12909..0000000000000000000000000000000000000000
--- a/ui/aura/focus_manager.cc
+++ /dev/null
@@ -1,105 +0,0 @@
-// 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/focus_manager.h"
-
-#include "ui/aura/client/activation_client.h"
-#include "ui/aura/client/focus_change_observer.h"
-#include "ui/aura/root_window.h"
-#include "ui/aura/window_delegate.h"
-
-namespace aura {
-
-////////////////////////////////////////////////////////////////////////////////
-// FocusManager, public:
-
-FocusManager::FocusManager() : focused_window_(NULL) {
-}
-
-FocusManager::~FocusManager() {
-}
-
-////////////////////////////////////////////////////////////////////////////////
-// FocusManager, client::FocusClient implementation:
-
-void FocusManager::AddObserver(client::FocusChangeObserver* observer) {
-  observers_.AddObserver(observer);
-}
-
-void FocusManager::RemoveObserver(client::FocusChangeObserver* observer) {
-  observers_.RemoveObserver(observer);
-}
-
-void FocusManager::FocusWindow(Window* focused_window) {
-  if (focused_window == focused_window_)
-    return;
-  if (focused_window && !focused_window->CanFocus())
-    return;
-  // The NULL-check of |focused_window| is essential here before asking the
-  // activation client, since it is valid to clear the focus by calling
-  // SetFocusedWindow() to NULL.
-
-  if (focused_window) {
-    RootWindow* root = focused_window->GetRootWindow();
-    DCHECK(root);
-    if (client::GetActivationClient(root) &&
-        !client::GetActivationClient(root)->OnWillFocusWindow(
-            focused_window, NULL)) {
-      return;
-    }
-  }
-
-  Window* old_focused_window = focused_window_;
-  focused_window_ = focused_window;
-
-  FOR_EACH_OBSERVER(client::FocusChangeObserver, observers_,
-                    OnWindowFocused(focused_window, old_focused_window));
-  client::FocusChangeObserver* observer =
-      client::GetFocusChangeObserver(old_focused_window);
-  if (observer)
-    observer->OnWindowFocused(focused_window_, old_focused_window);
-  observer = client::GetFocusChangeObserver(focused_window_);
-  if (observer)
-    observer->OnWindowFocused(focused_window_, old_focused_window);
-}
-
-void FocusManager::ResetFocusWithinActiveWindow(Window* window) {
-  FocusWindow(window);
-}
-
-Window* FocusManager::GetFocusedWindow() {
-  return focused_window_;
-}
-
-void FocusManager::OnWindowHiddenInRootWindow(
-    aura::Window* window,
-    aura::RootWindow* root_window,
-    bool destroyed) {
-  Window* focused_window =
-      client::GetFocusClient(root_window)->GetFocusedWindow();
-  if (window->Contains(focused_window)) {
-    Window* focus_to = window->transient_parent();
-    if (focus_to) {
-      // Has to be removed from the transient parent before focusing,
-      // otherwise |window| will be focused again.
-      if (destroyed)
-        focus_to->RemoveTransientChild(window);
-    } else {
-      // If the invisible view has no visible transient window, focus to the
-      // topmost visible parent window.
-      focus_to = window->parent();
-    }
-    if (focus_to &&
-        (!focus_to->IsVisible() ||
-          !focus_to->CanFocus() ||
-          (client::GetActivationClient(root_window) &&
-          !client::GetActivationClient(root_window)->OnWillFocusWindow(
-              focus_to, NULL)))) {
-      focus_to = NULL;
-    }
-    client::GetFocusClient(root_window)->FocusWindow(focus_to);
-  }
-}
-
-}  // namespace aura