Convert some component source sets to static library

components/filesystem/BUILD.gn

 # Copyright 2014 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("//services/shell/public/cpp/service.gni")
 import("//services/shell/public/service_manifest.gni")
 import("//testing/test.gni")
 
-source_set("lib") {
+static_library("lib") {
   sources = [
     "directory_impl.cc",
     "directory_impl.h",
     "file_impl.cc",
     "file_impl.h",
     "file_system_impl.cc",
     "file_system_impl.h",
     "lock_table.cc",
     "lock_table.h",
     "shared_temp_dir.cc",
@@ skipping 65 matching lines @@
     ":test_manifest",
     ":filesystem",
   ]
 }
 
 service_manifest("test_manifest") {
   type = "exe"
   name = "filesystem_service_unittests"
   source = "test_manifest.json"
 }