Remove unused file picture_serializer. (#6179)

ci/licenses_golden/licenses_flutter

@@ -819,8 +819,6 @@ FILE: ../../../flutter/shell/common/animator.cc
 FILE: ../../../flutter/shell/common/animator.h
 FILE: ../../../flutter/shell/common/engine.cc
 FILE: ../../../flutter/shell/common/engine.h
-FILE: ../../../flutter/shell/common/picture_serializer.cc
-FILE: ../../../flutter/shell/common/picture_serializer.h
 FILE: ../../../flutter/shell/common/platform_view.cc
 FILE: ../../../flutter/shell/common/platform_view.h
 FILE: ../../../flutter/shell/common/rasterizer.cc

shell/common/BUILD.gn

@@ -67,8 +67,6 @@ source_set("common") {
     "io_manager.h",
     "isolate_configuration.cc",
     "isolate_configuration.h",
-    "picture_serializer.cc",
-    "picture_serializer.h",
     "platform_view.cc",
     "platform_view.h",
     "rasterizer.cc",

shell/common/picture_serializer.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 "flutter/shell/common/picture_serializer.h"
-
-#include "third_party/skia/include/core/SkStream.h"
-
-namespace shell {
-
-void SerializePicture(const std::string& path, SkPicture* picture) {
-  SkFILEWStream stream(path.c_str());
-  picture->serialize(&stream);
-}
-
-}  // namespace shell

shell/common/picture_serializer.h

-// 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.
-
-#ifndef SHELL_GPU_PICTURE_SERIALIZER_H_
-#define SHELL_GPU_PICTURE_SERIALIZER_H_
-
-#include <string>
-
-#include "third_party/skia/include/core/SkPicture.h"
-
-namespace shell {
-
-void SerializePicture(const std::string& path, SkPicture* picture);
-
-}  // namespace shell
-
-#endif  // SHELL_GPU_PICTURE_SERIALIZER_H_