Move chrome.fileSystem implementation to //extensions

extensions/browser/api/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("//extensions/common/api/schema.gni")
 import("//tools/json_schema_compiler/json_schema_api.gni")
 
 source_set("api") {
   sources = [
     "api_resource.cc",
@@ skipping 35 matching lines @@
     "//extensions/browser/api/bluetooth_low_energy",
     "//extensions/browser/api/bluetooth_socket",
     "//extensions/browser/api/cast_channel",
     "//extensions/browser/api/declarative",
     "//extensions/browser/api/declarative_content",
     "//extensions/browser/api/declarative_webrequest",
     "//extensions/browser/api/display_source",
     "//extensions/browser/api/dns",
     "//extensions/browser/api/document_scan",
     "//extensions/browser/api/file_handlers",
+    "//extensions/browser/api/file_system",
     "//extensions/browser/api/hid",
     "//extensions/browser/api/idle",
     "//extensions/browser/api/management",
     "//extensions/browser/api/messaging",
     "//extensions/browser/api/metrics_private",
     "//extensions/browser/api/mime_handler_private",
     "//extensions/browser/api/networking_private",
     "//extensions/browser/api/power",
     "//extensions/browser/api/printer_provider",
     "//extensions/browser/api/printer_provider_internal",
@@ skipping 72 matching lines @@
   root_namespace = extensions_api_root_namespace
   uncompiled_sources = extensions_api_uncompiled_sources
 
   deps = [
     ":api",
     "//device/serial",
     "//extensions/common/api",
     "//skia",
   ]
 }