Create native_viewport_service, don't build it into mojo_shell unless Android

mojo/services/window_manager/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")
 
 if (use_aura) {
 
 import("//mojo/system.gni")
 
@@ skipping 50 matching lines @@
     "//mojo/services/public/cpp/view_manager",
     "//mojo/services/public/interfaces/view_manager",
     "//mojo/services/public/interfaces/window_manager",
     "//mojo/shell:test_support",
     "//mojo/system",
     "//testing/gtest",
     "//ui/gl",
   ]
   if (is_linux) {
     deps += [
-      "//third_party/mesa:osmesa",
-      "//mojo/services/native_viewport",
+      "//mojo/services/public/interfaces/native_viewport",
     ]
   }
   if (use_x11) {
     deps += [ "//ui/gfx/x" ]
   }
 }
 
 }  # use_aura