stop using SkXfermode -- use SkBlendMode instead

ash/mus/frame/custom_frame_view_mus.cc

 // Copyright 2016 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/mus/frame/custom_frame_view_mus.h"
 
 #include "ui/compositor/paint_cache.h"
 #include "ui/compositor/paint_recorder.h"
 #include "ui/gfx/canvas.h"
 
 namespace ash {
 namespace mus {
 
 CustomFrameViewMus::CustomFrameViewMus(
     views::Widget* widget,
     ImmersiveFullscreenControllerDelegate* immersive_delegate,
     bool enable_immersive)
     : CustomFrameViewAsh(widget, immersive_delegate, enable_immersive) {}
 
 CustomFrameViewMus::~CustomFrameViewMus() {}
 
 void CustomFrameViewMus::OnPaint(gfx::Canvas* canvas) {
   canvas->Save();
   CustomFrameViewAsh::OnPaint(canvas);
   canvas->Restore();
 
   // The client app draws the client area. Make ours totally transparent so
   // we only see the client app's client area.
   canvas->FillRect(GetBoundsForClientView(), SK_ColorBLACK,
-                   SkXfermode::kClear_Mode);
+                   SkBlendMode::kClear);
 }
 
 void CustomFrameViewMus::PaintChildren(const ui::PaintContext& context) {
   CustomFrameViewAsh::PaintChildren(context);
   // The client app draws the client area. Make ours totally transparent so
   // we only see the client apps client area.
   ui::PaintRecorder recorder(context, size(), &paint_cache_);
   recorder.canvas()->FillRect(GetBoundsForClientView(), SK_ColorBLACK,
-                              SkXfermode::kClear_Mode);
+                              SkBlendMode::kClear);
 }
 
 }  // namespace mus
 }  // namespace ash