Sort GYP and GN files under ppapi

ppapi/examples/video_decode/BUILD.gn

 # 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.
 
 import("//ppapi/examples/ppapi_example.gni")
 
 group("video_decode") {
   testonly = true
   deps = [
     ":dev",
     ":stable",
   ]
 }
 
 ppapi_example("dev") {
   output_name = "ppapi_example_video_decode_dev"
   sources = [
+    "testdata.h",
     "video_decode_dev.cc",
-    "testdata.h",
   ]
   deps = [
     "//ppapi/cpp",
     "//ppapi/lib/gl/gles2",
   ]
 }
 
 ppapi_example("stable") {
   output_name = "ppapi_example_video_decode"
   sources = [
+    "testdata.h",
     "video_decode.cc",
-    "testdata.h",
   ]
   deps = [
     "//ppapi/cpp",
     "//ppapi/lib/gl/gles2",
   ]
 }