Allow native_viewport to create new native windows on demand on Android.

services/native_viewport/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/ui.gni")
 import("//mojo/public/mojo_application.gni")
 
 if (is_android) {
   import("//build/config/android/config.gni")
   import("//build/config/android/rules.gni")
+  import("//mojo/public/tools/bindings/mojom.gni")
 
   group("native_viewport") {
     deps = [
       ":lib",
       ":native_viewport_java",
       ":jni_headers",
     ]
   }
 
   android_library("native_viewport_java") {
     java_files =
         [ "android/src/org/chromium/mojo/PlatformViewportAndroid.java" ]
 
     deps = [
       "//base:base_java",
       "//services/keyboard",
       "//mojo/services/keyboard/public/interfaces:interfaces_java",
       "//mojo/public/java:bindings",
       "//mojo/public/java:system",
     ]
   }
 
   generate_jni("jni_headers") {
     sources = [
       "android/src/org/chromium/mojo/PlatformViewportAndroid.java",
     ]
 
     jni_package = "mojo"
   }
+
+  mojom("interfaces") {
+    sources = [
+      "native_viewport_internal.mojom",
+    ]
+  }
 } else {
   mojo_native_application("native_viewport") {
     output_name = "native_viewport_service"
     sources = [
       "main.cc",
     ]
     deps = [
       ":lib",
       "//base",
       "//mojo/application",
@@ skipping 43 matching lines @@
     "//mojo/services/native_viewport/public/interfaces",
     "//ui/events",
     "//ui/events/platform",
     "//ui/gfx",
     "//ui/gfx/geometry",
     "//ui/gl",
     "//ui/platform_window",
   ]
 
   if (is_android) {
-    deps += [ ":jni_headers" ]
+    deps += [
+      ":interfaces",
+      ":jni_headers",
+    ]
   }
 
   if (use_x11) {
     deps += [ "//ui/platform_window/x11" ]
   } else {
     sources -= [ "platform_viewport_x11.cc" ]
   }
 
   if (is_win) {
     deps += [ "//ui/platform_window/win" ]
   }
 }