Migrate content/common/gpu/media code to media/gpu

media/gpu/vp9_picture.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 "content/common/gpu/media/vp9_picture.h"
+#include "media/gpu/vp9_picture.h"
 
-namespace content {
+namespace media {
 
 VP9Picture::VP9Picture() {}
 
 VP9Picture::~VP9Picture() {}
 
 V4L2VP9Picture* VP9Picture::AsV4L2VP9Picture() {
   return nullptr;
 }
 
 VaapiVP9Picture* VP9Picture::AsVaapiVP9Picture() {
   return nullptr;
 }
 
-}  // namespace content
+}  // namespace media