[webnfc] Implement push method for Android nfc mojo service.

device/nfc/BUILD.gn

 # Copyright 2014 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("//mojo/public/tools/bindings/mojom.gni")
 
 static_library("nfc") {
   sources = [
     "nfc_adapter.cc",
@@ skipping 42 matching lines @@
 
   defines = [ "DEVICE_NFC_IMPLEMENTATION" ]
 
   deps = [
     ":mojo_bindings",
     "//base",
     "//base/third_party/dynamic_annotations",
     "//mojo/edk/system",
     "//mojo/public/cpp/bindings",
   ]
+
+  if (is_android) {
+    sources -= [ "nfc_impl_default.cc" ]
+  }
 }
 
 mojom("mojo_bindings") {
   sources = [
     "nfc.mojom",
   ]
 }