Convert //chrome/browser/ui from scoped_ptr to std::unique_ptr

chrome/browser/ui/cocoa/native_window_tracker_cocoa.mm

 // 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 "chrome/browser/ui/cocoa/native_window_tracker_cocoa.h"
 
 #import <AppKit/AppKit.h>
 
 @interface BridgedNativeWindowTracker : NSObject {
  @private
@@ skipping 42 matching lines @@
 }
 
 NativeWindowTrackerCocoa::~NativeWindowTrackerCocoa() {
 }
 
 bool NativeWindowTrackerCocoa::WasNativeWindowClosed() const {
   return [bridge_ wasNSWindowClosed];
 }
 
 // static
-scoped_ptr<NativeWindowTracker> NativeWindowTracker::Create(
+std::unique_ptr<NativeWindowTracker> NativeWindowTracker::Create(
     gfx::NativeWindow window) {
-  return scoped_ptr<NativeWindowTracker>(new NativeWindowTrackerCocoa(window));
+  return std::unique_ptr<NativeWindowTracker>(
+      new NativeWindowTrackerCocoa(window));
 }