Generalize layer mirroring for phantom windows

ui/views/cocoa/bridged_native_widget.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.
 
 #import "ui/views/cocoa/bridged_native_widget.h"
 
 #import <objc/runtime.h>
 #include <stddef.h>
 #include <stdint.h>
 
 #include "base/logging.h"
 #import "base/mac/foundation_util.h"
 #include "base/mac/mac_util.h"
 #import "base/mac/sdk_forward_declarations.h"
+#include "base/memory/ptr_util.h"
 #include "base/threading/thread_task_runner_handle.h"
 #include "ui/accelerated_widget_mac/window_resize_helper_mac.h"
 #import "ui/base/cocoa/constrained_window/constrained_window_animation.h"
 #include "ui/base/hit_test.h"
 #include "ui/base/ime/input_method.h"
 #include "ui/base/ime/input_method_factory.h"
 #include "ui/display/display.h"
 #include "ui/display/screen.h"
 #include "ui/gfx/geometry/dip_util.h"
 #import "ui/gfx/mac/coordinate_conversion.h"
@@ skipping 955 matching lines @@
 }
 
 void BridgedNativeWidget::CreateLayer(ui::LayerType layer_type,
                                       bool translucent) {
   DCHECK(bridged_view_);
   DCHECK(!layer());
 
   CreateCompositor();
   DCHECK(compositor_);
 
-  SetLayer(new ui::Layer(layer_type));
+  SetLayer(base::MakeUnique<ui::Layer>(layer_type));
   // Note, except for controls, this will set the layer to be hidden, since it
   // is only called during Init().
   layer()->SetVisible(window_visible_);
   layer()->set_delegate(this);
 
   InitCompositor();
 
   // Transparent window support.
   layer()->GetCompositor()->SetHostHasTransparentBackground(translucent);
   layer()->SetFillsBoundsOpaquely(!translucent);
@@ skipping 401 matching lines @@
   [bridged_view_ setMouseDownCanMoveWindow:draggable];
   // AppKit will not update its cache of mouseDownCanMoveWindow unless something
   // changes. Previously we tried adding an NSView and removing it, but for some
   // reason it required reposting the mouse-down event, and didn't always work.
   // Calling the below seems to be an effective solution.
   [window_ setMovableByWindowBackground:NO];
   [window_ setMovableByWindowBackground:YES];
 }
 
 }  // namespace views