Move enable_webrtc to a buildflag header.

components/nacl/common/BUILD.gn

 # Copyright 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.
 
 import("//build/config/features.gni")
 
 if (enable_nacl) {
   # This is separate so it can be used by ../broker:nacl64.
   static_library("minimal") {
     sources = [
@@ skipping 29 matching lines @@
   # depend on //content/public/common or anything like that, because that
   # would bring in lots more than counts as "minimal" (stuff that should
   # not be in the nacl64.exe build).
   source_set("minimal_content_dummy") {
     check_includes = false
     sources = [
       "//content/public/common/content_switches.h",
       "//content/public/common/process_type.h",
       "//content/public/common/sandbox_type.h",
     ]
+
+    # Deps required by the above headers.
+    deps = [
+      "//media:media_features",
+    ]
   }
 
   static_library("common") {
     sources = [
       "nacl_host_messages.cc",
       "nacl_host_messages.h",
       "nacl_nonsfi_util.cc",
       "nacl_nonsfi_util.h",
       "pnacl_types.cc",
       "pnacl_types.h",
@@ skipping 44 matching lines @@
     "//content/public/common",
   ]
 }
 
 static_library("switches") {
   sources = [
     "nacl_switches.cc",
     "nacl_switches.h",
   ]
 }