Add FlStandardCodec

Author: robert-ancell

ci/licenses_golden/licenses_flutter

@@ -1187,6 +1187,8 @@ FILE: ../../../flutter/shell/platform/linux/fl_renderer.cc
 FILE: ../../../flutter/shell/platform/linux/fl_renderer.h
 FILE: ../../../flutter/shell/platform/linux/fl_renderer_x11.cc
 FILE: ../../../flutter/shell/platform/linux/fl_renderer_x11.h
+FILE: ../../../flutter/shell/platform/linux/fl_standard_codec.cc
+FILE: ../../../flutter/shell/platform/linux/fl_standard_codec_test.cc
 FILE: ../../../flutter/shell/platform/linux/fl_string_codec.cc
 FILE: ../../../flutter/shell/platform/linux/fl_string_codec_test.cc
 FILE: ../../../flutter/shell/platform/linux/fl_value.cc
@@ -1198,6 +1200,7 @@ FILE: ../../../flutter/shell/platform/linux/public/flutter_linux/fl_binary_messe
 FILE: ../../../flutter/shell/platform/linux/public/flutter_linux/fl_dart_project.h
 FILE: ../../../flutter/shell/platform/linux/public/flutter_linux/fl_engine.h
 FILE: ../../../flutter/shell/platform/linux/public/flutter_linux/fl_message_codec.h
+FILE: ../../../flutter/shell/platform/linux/public/flutter_linux/fl_standard_codec.h
 FILE: ../../../flutter/shell/platform/linux/public/flutter_linux/fl_string_codec.h
 FILE: ../../../flutter/shell/platform/linux/public/flutter_linux/fl_value.h
 FILE: ../../../flutter/shell/platform/linux/public/flutter_linux/fl_view.h

shell/platform/linux/BUILD.gn

@@ -50,6 +50,7 @@ _public_headers = [
   "public/flutter_linux/fl_dart_project.h",
   "public/flutter_linux/fl_engine.h",
   "public/flutter_linux/fl_message_codec.h",
+  "public/flutter_linux/fl_standard_codec.h",
   "public/flutter_linux/fl_string_codec.h",
   "public/flutter_linux/fl_value.h",
   "public/flutter_linux/fl_view.h",
@@ -72,6 +73,7 @@ source_set("flutter_linux") {
     "fl_message_codec.cc",
     "fl_renderer.cc",
     "fl_renderer_x11.cc",
+    "fl_standard_codec.cc",
     "fl_string_codec.cc",
     "fl_value.cc",
     "fl_view.cc",
@@ -102,6 +104,7 @@ executable("flutter_linux_unittests") {
     "fl_binary_codec_test.cc",
     "fl_dart_project_test.cc",
     "fl_message_codec_test.cc",
+    "fl_standard_codec_test.cc",
     "fl_string_codec_test.cc",
     "fl_value_test.cc",
     "testing/fl_test.cc",