Land prep work to enable NaCl in the Linux x64 GN builds.

components/nacl/renderer/plugin/BUILD.gn

+# Copyright (c) 2015 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.
+
+source_set("nacl_trusted_plugin") {
+  sources = [
+    "module_ppapi.cc",
+    "nacl_subprocess.cc",
+    "plugin.cc",
+    "pnacl_coordinator.cc",
+    "pnacl_resources.cc",
+    "pnacl_translate_thread.cc",
+    "ppapi_entrypoints.cc",
+    "sel_ldr_launcher_chrome.cc",
+    "service_runtime.cc",
+    "srpc_client.cc",
+    "srpc_params.cc",
+    "temporary_file.cc",
+    "utility.cc",
+  ]
+
+  deps = [
+    "//media:shared_memory_support",
+    "//native_client/src/shared/gio",
+    "//native_client/src/shared/imc",
+    "//native_client/src/shared/platform",
+    "//native_client/src/trusted/desc:nrd_xfer",
+    "//native_client/src/trusted/nonnacl_util:sel_ldr_launcher_base",
+    "//native_client/src/trusted/platform_qualify:platform_qual_lib",
+    "//native_client/src/trusted/simple_service",
+    "//native_client/src/trusted/weak_ref",
+    "//ppapi/cpp:objects",
+    "//ppapi/cpp/private:internal_module",
+  ]
+
+  if (is_linux) {
+    cflags = [ "-Wno-long-long" ]
+
+    ldflags = [ "-Wl,-z,defs" ]
+
+    libs = [ "dl" ]
+  }
+}