Replace scoped_ptr with std::unique_ptr in //ui

ui/aura/window_tree_host_platform.cc

 // Copyright 2015 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/window_tree_host_platform.h"
 
 #include <utility>
 
 #include "base/trace_event/trace_event.h"
 #include "build/build_config.h"
@@ skipping 39 matching lines @@
 #endif
 }
 
 WindowTreeHostPlatform::WindowTreeHostPlatform()
     : widget_(gfx::kNullAcceleratedWidget),
       current_cursor_(ui::kCursorNull) {
   CreateCompositor();
 }
 
 void WindowTreeHostPlatform::SetPlatformWindow(
-    scoped_ptr<ui::PlatformWindow> window) {
+    std::unique_ptr<ui::PlatformWindow> window) {
   window_ = std::move(window);
 }
 
 WindowTreeHostPlatform::~WindowTreeHostPlatform() {
   DestroyCompositor();
   DestroyDispatcher();
 }
 
 ui::EventSource* WindowTreeHostPlatform::GetEventSource() {
   return this;
@@ skipping 108 matching lines @@
   DCHECK_EQ(widget, widget_);
   widget_ = gfx::kNullAcceleratedWidget;
 }
 
 void WindowTreeHostPlatform::OnActivationChanged(bool active) {
   if (active)
     OnHostActivated();
 }
 
 }  // namespace aura