Componentize safe_browsing [X+1] : move the renderer part to component.

components/safe_browsing/common/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("//third_party/protobuf/proto_library.gni")
+
 source_set("common") {
   sources = [
     "safebrowsing_constants.cc",
     "safebrowsing_constants.h",
     "safebrowsing_message_generator.cc",
     "safebrowsing_message_generator.h",
     "safebrowsing_messages.h",
     "safebrowsing_switches.cc",
     "safebrowsing_switches.h",
   ]
 
   deps = [
     "//base",
     "//ipc",
     "//url/ipc:url_ipc",
   ]
 }