Remove linked_ptr from ash

ash/wm/resize_shadow_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 "ash/wm/resize_shadow_controller.h"
 
 #include <utility>
 
 #include "ash/wm/resize_shadow.h"
 #include "ui/aura/window.h"
 
 namespace ash {
 
 ResizeShadowController::ResizeShadowController() {}
 
 ResizeShadowController::~ResizeShadowController() {
-  for (WindowShadowMap::const_iterator it = window_shadows_.begin();
-       it != window_shadows_.end(); ++it) {
-    it->first->RemoveObserver(this);
-  }
+  for (const auto& shadow : window_shadows_)
+    shadow.first->RemoveObserver(this);
 }
 
 void ResizeShadowController::ShowShadow(aura::Window* window, int hit_test) {
   ResizeShadow* shadow = GetShadowForWindow(window);
   if (!shadow)
     shadow = CreateShadow(window);
   shadow->ShowForHitTest(hit_test);
 }
 
 void ResizeShadowController::HideShadow(aura::Window* window) {
@@ skipping 14 matching lines @@
   ResizeShadow* shadow = GetShadowForWindow(window);
   if (shadow)
     shadow->Layout(new_bounds);
 }
 
 void ResizeShadowController::OnWindowDestroyed(aura::Window* window) {
   window_shadows_.erase(window);
 }
 
 ResizeShadow* ResizeShadowController::CreateShadow(aura::Window* window) {
-  linked_ptr<ResizeShadow> shadow(new ResizeShadow());
-  window_shadows_.insert(std::make_pair(window, shadow));
+  std::unique_ptr<ResizeShadow> shadow(new ResizeShadow());

[oshima, 2016/11/04 18:31:43]

optional: or auto..MakeUnique. 

[limasdf, 2016/11/05 06:08:17]

any advantage in using it? to use it we need to additional header(ptr_util.h).

[limasdf, 2016/11/05 06:12:57]

Ah, I got it. using auto..MakeUnique calls 'new' only once.
Done.

   // Attach the layers to this window.
   shadow->Init(window);
   // Ensure initial bounds are correct.
   shadow->Layout(window->bounds());
   // Watch for bounds changes.
   window->AddObserver(this);
-  return shadow.get();
+
+  ResizeShadow* raw_shadow = shadow.get();
+  window_shadows_.insert(std::make_pair(window, std::move(shadow)));
+  return raw_shadow;
 }
 
 ResizeShadow* ResizeShadowController::GetShadowForWindow(aura::Window* window) {
-  WindowShadowMap::const_iterator it = window_shadows_.find(window);
-  return it != window_shadows_.end() ? it->second.get() : NULL;
+  auto it = window_shadows_.find(window);
+  return it != window_shadows_.end() ? it->second.get() : nullptr;
 }
 
 }  // namespace ash