Moves TransientWindowClient to ui/aura/client and adds observer

ui/wm/core/transient_window_manager.cc

 // 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.
 
 #include "ui/wm/core/transient_window_manager.h"
 
 #include <algorithm>
 #include <functional>
 
 #include "base/auto_reset.h"
 #include "base/stl_util.h"
+#include "ui/aura/client/transient_window_client_observer.h"
 #include "ui/aura/window.h"
 #include "ui/aura/window_property.h"
 #include "ui/aura/window_tracker.h"
+#include "ui/wm/core/transient_window_controller.h"
 #include "ui/wm/core/transient_window_observer.h"
 #include "ui/wm/core/transient_window_stacking_client.h"
 #include "ui/wm/core/window_util.h"
 
 using aura::Window;
 
 DECLARE_WINDOW_PROPERTY_TYPE(wm::TransientWindowManager*);
 
 namespace wm {
 namespace {
@@ skipping 35 matching lines @@
   DCHECK(TransientWindowStackingClient::instance_);
 
   TransientWindowManager* child_manager = Get(child);
   if (child_manager->transient_parent_)
     Get(child_manager->transient_parent_)->RemoveTransientChild(child);
   DCHECK(std::find(transient_children_.begin(), transient_children_.end(),
                    child) == transient_children_.end());
   transient_children_.push_back(child);
   child_manager->transient_parent_ = window_;
 
+  for (aura::client::TransientWindowClientObserver& observer :
+       TransientWindowController::Get()->observers_) {
+    observer.OnTransientChildWindowAdded(window_, child);
+  }
+
   // Restack |child| properly above its transient parent, if they share the same
   // parent.
   if (child->parent() == window_->parent())
     RestackTransientDescendants();
 
   for (auto& observer : observers_)
     observer.OnTransientChildAdded(window_, child);
 }
 
 void TransientWindowManager::RemoveTransientChild(Window* child) {
   Windows::iterator i =
       std::find(transient_children_.begin(), transient_children_.end(), child);
   DCHECK(i != transient_children_.end());
   transient_children_.erase(i);
   TransientWindowManager* child_manager = Get(child);
   DCHECK_EQ(window_, child_manager->transient_parent_);
-  child_manager->transient_parent_ = NULL;
+  child_manager->transient_parent_ = nullptr;
+
+  for (aura::client::TransientWindowClientObserver& observer :
+       TransientWindowController::Get()->observers_) {
+    observer.OnTransientChildWindowRemoved(window_, child);
+  }
 
   // If |child| and its former transient parent share the same parent, |child|
   // should be restacked properly so it is not among transient children of its
   // former parent, anymore.
   if (window_->parent() == child->parent())
     RestackTransientDescendants();
 
   for (auto& observer : observers_)
     observer.OnTransientChildRemoved(window_, child);
 }
@@ skipping 120 matching lines @@
 
   // Destroy transient children, only after we've removed ourselves from our
   // parent, as destroying an active transient child may otherwise attempt to
   // refocus us.
   Windows transient_children(transient_children_);
   base::STLDeleteElements(&transient_children);
   DCHECK(transient_children_.empty());
 }
 
 }  // namespace wm