Add 'Flog' formatted logging to mojo/services

mojo/services/flog/cpp/BUILD.gn

 # 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.
 
 import("//build/module_args/mojo.gni")
 import("$mojo_sdk_root/mojo/public/mojo_sdk.gni")
 
-source_set("framework_create") {
+mojo_sdk_source_set("cpp") {
   sources = [
-    "decoder.cc",
-    "demux.cc",
+    "flog.cc",
+    "flog.h",
   ]
 
   deps = [
-    "//services/media/framework",
-    "//services/media/framework_ffmpeg",
+    "$mojo_sdk_root/mojo/public/cpp/application",
+    "$mojo_sdk_root/mojo/public/cpp/bindings",
+    "$mojo_sdk_root/mojo/public/cpp/environment",
+    "$mojo_sdk_root/mojo/services/flog/interfaces",
   ]
 }