Reduce APK size by disabling WebRTC.

remoting/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")
 import("//build/config/ui.gni")
 import("//build/util/version.gni")
 import("//remoting/remoting_version.gni")
 import("//remoting/remoting_enable.gni")
 import("//testing/test.gni")
 
 # Various remoting targets need this version definition.
 config("version") {
   defines = [ "VERSION=$chrome_version_full" ]
 }
 
+config("webrtc") {
+  if (!is_official_build && !is_nacl) {
+    defines = [ "ENABLE_WEBRTC_REMOTING_CLIENT=1" ]
+  }
+}
+
 group("remoting_all") {
   testonly = true
 
   deps = [
     #"//remoting:remoting_browser_test_resources",
     "//remoting:remoting_unittests",
     "//remoting/test:chromoting_test_driver",
 
     #"//remoting:remoting_webapp_unittests",
     #"//app_remoting_test.gyp:ar_sample_test_driver",
@@ skipping 161 matching lines @@
 
       if (enable_webrtc) {
         deps += [ "//third_party/libjingle:libjingle_webrtc" ]
       }
     }
   }
 } else {
   group("remoting_unittests") {
   }
 }