Decompose //extensions/browser/BUILD.gn

extensions/browser/api/bluetooth_socket/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.
 
-component("range") {
+source_set("bluetooth_socket") {
   sources = [
-    "gfx_range_export.h",
-    "range.cc",
-    "range.h",
-    "range_f.cc",
-    "range_f.h",
-    "range_mac.mm",
-    "range_win.cc",
+    "bluetooth_api_socket.cc",
+    "bluetooth_api_socket.h",
+    "bluetooth_socket_api.cc",
+    "bluetooth_socket_api.h",
+    "bluetooth_socket_event_dispatcher.cc",
+    "bluetooth_socket_event_dispatcher.h",
   ]
 
   configs += [
     # TODO(jschuh): crbug.com/167187 fix size_t to int truncations.
     "//build/config/compiler:no_size_t_to_int_warning",
   ]
 
-  defines = [ "GFX_RANGE_IMPLEMENTATION" ]
-
   deps = [
-    "//base",
-    "//ui/gfx:gfx_export",
+    "//extensions/common/api",
   ]
 }