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

mojo/shell/BUILD.gn

Index: mojo/shell/BUILD.gn
diff --git a/mojo/shell/BUILD.gn b/mojo/shell/BUILD.gn
index eb62ff2adf8d2bfd6bbe349212267957a123dc32..a69dcf068dd4dbfa842e77f3d2af4c9a1e9e67a0 100644
--- a/mojo/shell/BUILD.gn
+++ b/mojo/shell/BUILD.gn
@@ -12,10 +12,6 @@ executable("mojo_shell") {
     "//mojo/common",
     "//mojo/environment:chromium",
     "//mojo/application_manager",
-    "//mojo/system",
-    "//third_party/icu",
-    "//ui/gl",
-    "//url",
   ]
 
   if (use_ozone) {
@@ -40,13 +36,9 @@ source_set("lib") {
     "//mojo/common",
     "//mojo/gles2",
     "//mojo/public/interfaces/application",
-    "//mojo/services/native_viewport",
-    "//mojo/services/public/interfaces/native_viewport",
     "//mojo/services/public/interfaces/network",
     "//mojo/spy",
     "//mojo/system",
-    "//net",
-    "//url",
   ]
 
   sources = [
@@ -89,6 +81,7 @@ source_set("lib") {
     ]
   } else if (is_android) {
     deps += [
+      "//mojo/services/native_viewport:lib",
       "//mojo/services/network:lib",
     ]
     sources += [
@@ -96,18 +89,6 @@ source_set("lib") {
       "network_application_loader.h",
     ]
   }
-  if (use_aura) {
-    deps += [
-      # These are only necessary as long as we hard code use of ViewManager.
-      "//skia",
-      "//mojo/services/view_manager",
-      "//mojo/services/public/interfaces/view_manager",
-    ]
-    sources += [
-      "view_manager_loader.cc",
-      "view_manager_loader.h",
-    ]
-  }
 }
 
 mojom("app_child_process_bindings") {