diff --git a/build/sky_app.gni b/build/sky_app.gni
index 34148ae2816..950bf82c78b 100644
--- a/build/sky_app.gni
+++ b/build/sky_app.gni
@@ -2,11 +2,16 @@
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
-import("//build/config/android/rules.gni")
 import("//sky/build/skyx.gni")
 
 template("sky_app") {
-  skyx("app") {
+  skyx_target_name = target_name
+
+  if (is_android) {
+    skyx_target_name = "app"
+  }
+
+  skyx(skyx_target_name) {
     main_dart = invoker.main_dart
 
     if (defined(invoker.manifest)) {
@@ -18,65 +23,65 @@ template("sky_app") {
     }
   }
 
-  bundle_prefix = target_name
+  if (is_android) {
+    import("//build/config/android/rules.gni")
 
-  copy("copy_${bundle_prefix}_bundle") {
-    sources = [
-      "$target_gen_dir/app.skyx",
-    ]
-    outputs = [
-      "$target_gen_dir/${bundle_prefix}.skyx",
-    ]
+    bundle_prefix = target_name
 
-    deps = [
-      ":app",
-    ]
-  }
+    copy("copy_${bundle_prefix}_bundle") {
+      sources = [
+        "$target_gen_dir/app.skyx",
+      ]
+      outputs = [
+        "$target_gen_dir/${bundle_prefix}.skyx",
+      ]
 
-  copy_ex("assets") {
-    clear_dir = true
-    dest = "$target_gen_dir/assets"
+      deps = [
+        ":app",
+      ]
+    }
 
-    sources = [
-      "$root_build_dir/icudtl.dat",
-    ]
-    deps = [
-      "//third_party/icu",
-    ]
+    copy_ex("assets") {
+      clear_dir = true
+      dest = "$target_gen_dir/assets"
 
-    if (enable_skyx) {
-      sources += [ "$target_gen_dir/app.skyx" ]
-      deps += [ ":copy_${bundle_prefix}_bundle" ]
+      sources = [
+        "$root_build_dir/icudtl.dat",
+        "$target_gen_dir/app.skyx",
+      ]
+      deps = [
+        "//third_party/icu",
+        ":copy_${bundle_prefix}_bundle",
+      ]
 
       if (defined(invoker.bundles)) {
         foreach(bundle, invoker.bundles) {
           bundle_gen_dir = get_label_info(bundle, "target_gen_dir")
           bundle_name = get_label_info(bundle, "name")
-
           sources += [ "$bundle_gen_dir/${bundle_name}.skyx" ]
           deps += [ bundle ]
         }
       }
     }
-  }
 
-  android_apk(target_name) {
-    apk_name = invoker.apk_name
-    android_manifest = "apk/AndroidManifest.xml"
+    android_apk(target_name) {
+      apk_name = invoker.apk_name
+      android_manifest = "apk/AndroidManifest.xml"
 
-    native_libs = [ "libsky_shell.so" ]
-    asset_location = "$target_gen_dir/assets"
+      native_libs = [ "libsky_shell.so" ]
+      asset_location = "$target_gen_dir/assets"
 
-    deps = [
-      "//base:base_java",
-      "//sky/shell:assets",
-      "//sky/shell:java",
-      "//sky/shell:sky_shell",
-      ":assets",
-    ]
+      deps = [
+        "//base:base_java",
+        "//sky/shell:assets",
+        "//sky/shell:java",
+        "//sky/shell:sky_shell",
+        ":assets",
+      ]
 
-    if (defined(invoker.deps)) {
-      deps += invoker.deps
+      if (defined(invoker.deps)) {
+        deps += invoker.deps
+      }
     }
   }
 }
diff --git a/build/skyx.gni b/build/skyx.gni
index 2306558d207..f0d9c235fb7 100644
--- a/build/skyx.gni
+++ b/build/skyx.gni
@@ -2,15 +2,6 @@
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
-declare_args() {
-  # Controls whether we build app.skyx bundles in the sky_app template below.
-  # An app.skyx bundle contains all the code an resources needed to run a Sky
-  # app offline. Unfortunately, we don't yet have all the Dart packages we need
-  # to create skyx packages installed on the build bots, so this functionality
-  # is currently disabled. This flag allows for local testing of this feature.
-  enable_skyx = false
-}
-
 package_root = "$root_gen_dir/dart-pkg/packages"
 
 template("skyx") {
@@ -75,6 +66,8 @@ template("skyx") {
 
     script = "//sky/tools/skyx.py"
     args = [
+      "--package-root",
+      rebase_path(package_root, root_build_dir),
       "--asset-base",
       rebase_path(asset_base, root_build_dir),
       "--snapshot",
@@ -93,14 +86,13 @@ template("skyx") {
 
     deps = [
       ":gen_${bundle_prefix}_snapshot",
+      "//third_party/dart-pkg",
     ]
   }
 
   group(target_name) {
-    if (enable_skyx) {
-      deps = [
-        ":gen_${bundle_prefix}_bundle",
-      ]
-    }
+    deps = [
+      ":gen_${bundle_prefix}_bundle",
+    ]
   }
 }
diff --git a/sdk/BUILD.gn b/sdk/BUILD.gn
index f742a8b23c9..5752963358e 100644
--- a/sdk/BUILD.gn
+++ b/sdk/BUILD.gn
@@ -92,7 +92,8 @@ dart_pkg("sky") {
 
   # List of mojom targets that the sky pkg exports
   deps = [
-    "//sky/services/engine",
+    "//sky/services/engine:interfaces",
+    "//sky/services/activity:interfaces",
   ]
 
   datadeps = [
@@ -100,7 +101,8 @@ dart_pkg("sky") {
     "//mojo/dart/mojom",
     "//mojo/public/dart:mojo",
     "//sky/engine/bindings",
-    "//sky/services/testing",
+    "//sky/services/testing:interfaces",
+    "//sky/services/media:interfaces",
     "//third_party/dart-pkg",
   ]
 
diff --git a/sdk/example/BUILD.gn b/sdk/example/BUILD.gn
index 950504a230b..96325eb18bd 100644
--- a/sdk/example/BUILD.gn
+++ b/sdk/example/BUILD.gn
@@ -5,15 +5,11 @@
 group("example") {
   testonly = true
 
-  deps = []
-
-  if (is_android) {
-    deps += [
-      "//sky/sdk/example/demo_launcher",
-      "//sky/sdk/example/mine_digger",
-      "//sky/sdk/example/rendering",
-      "//sky/sdk/example/stocks",
-      "//sky/sdk/example/widgets",
-    ]
-  }
+  deps = [
+    "//sky/sdk/example/rendering",
+    "//sky/sdk/example/demo_launcher",
+    "//sky/sdk/example/mine_digger",
+    "//sky/sdk/example/stocks",
+    "//sky/sdk/example/widgets",
+  ]
 }
diff --git a/sdk/example/demo_launcher/BUILD.gn b/sdk/example/demo_launcher/BUILD.gn
index b7bf617d529..fbae9b404dd 100644
--- a/sdk/example/demo_launcher/BUILD.gn
+++ b/sdk/example/demo_launcher/BUILD.gn
@@ -5,21 +5,22 @@
 import("//sky/build/sky_app.gni")
 
 sky_app("demo_launcher") {
-  apk_name = "SkyDemo"
   main_dart = "lib/main.dart"
   manifest = "sky.yaml"
 
-  if (enable_skyx) {
+  if (is_android) {
+    apk_name = "SkyDemo"
+
     bundles = [
       "//sky/sdk/example/mine_digger",
       "//sky/sdk/example/rendering:interactive_flex",
       "//sky/sdk/example/stocks",
       "//sky/sdk/example/widgets:sector",
     ]
-  }
 
-  deps = [
-    "//sky/sdk/example/demo_launcher/apk:java",
-    "//sky/sdk/example/demo_launcher/apk:resources",
-  ]
+    deps = [
+      "//sky/sdk/example/demo_launcher/apk:java",
+      "//sky/sdk/example/demo_launcher/apk:resources",
+    ]
+  }
 }
diff --git a/sdk/example/mine_digger/BUILD.gn b/sdk/example/mine_digger/BUILD.gn
index 3472599a817..ec5218b15ae 100644
--- a/sdk/example/mine_digger/BUILD.gn
+++ b/sdk/example/mine_digger/BUILD.gn
@@ -2,11 +2,12 @@
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
-assert(is_android)
-
 import("//sky/build/sky_app.gni")
 
 sky_app("mine_digger") {
-  apk_name = "MineDigger"
   main_dart = "lib/main.dart"
+
+  if (is_android) {
+    apk_name = "MineDigger"
+  }
 }
diff --git a/sdk/example/stocks/BUILD.gn b/sdk/example/stocks/BUILD.gn
index 0e56d1536f4..d1484fdd5e4 100644
--- a/sdk/example/stocks/BUILD.gn
+++ b/sdk/example/stocks/BUILD.gn
@@ -2,12 +2,13 @@
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
-assert(is_android)
-
 import("//sky/build/sky_app.gni")
 
 sky_app("stocks") {
-  apk_name = "Stocks"
   main_dart = "lib/main.dart"
   manifest = "sky.yaml"
+
+  if (is_android) {
+    apk_name = "Stocks"
+  }
 }
diff --git a/services/activity/BUILD.gn b/services/activity/BUILD.gn
index ee5dbf3b5c4..e55ee07a619 100644
--- a/services/activity/BUILD.gn
+++ b/services/activity/BUILD.gn
@@ -16,6 +16,12 @@ group("activity") {
   }
 }
 
+mojom("interfaces") {
+  sources = [
+    "activity.mojom",
+  ]
+}
+
 if (is_android) {
   import("//build/config/android/config.gni")
   import("//build/config/android/rules.gni")
@@ -31,9 +37,3 @@ if (is_android) {
     ]
   }
 }
-
-mojom("interfaces") {
-  sources = [
-    "activity.mojom",
-  ]
-}
diff --git a/services/engine/BUILD.gn b/services/engine/BUILD.gn
index 667384f011d..f01238aa24c 100644
--- a/services/engine/BUILD.gn
+++ b/services/engine/BUILD.gn
@@ -4,7 +4,7 @@
 
 import("//mojo/public/tools/bindings/mojom.gni")
 
-mojom("engine") {
+mojom("interfaces") {
   sources = [
     "input_event.mojom",
     "sky_engine.mojom",
diff --git a/services/media/BUILD.gn b/services/media/BUILD.gn
index f6b701342a2..9cc1afd2403 100644
--- a/services/media/BUILD.gn
+++ b/services/media/BUILD.gn
@@ -2,32 +2,18 @@
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
-import("//build/config/android/config.gni")
-import("//build/config/android/rules.gni")
 import("//mojo/public/tools/bindings/mojom.gni")
 
 group("media") {
   testonly = true
 
   deps = [
-    ":media_lib",
     ":interfaces",
   ]
-}
 
-android_library("media_lib") {
-  java_files = [
-    "src/org/domokit/media/MediaPlayerImpl.java",
-    "src/org/domokit/media/MediaServiceImpl.java",
-  ]
-
-  deps = [
-    "//base:base_java",
-    "//mojo/java",
-    "//mojo/public/java:bindings",
-    "//mojo/public/java:system",
-    ":interfaces_java",
-  ]
+  if (is_android) {
+    deps += [ ":media_lib" ]
+  }
 }
 
 mojom("interfaces") {
@@ -35,3 +21,23 @@ mojom("interfaces") {
     "media.mojom",
   ]
 }
+
+if (is_android) {
+  import("//build/config/android/config.gni")
+  import("//build/config/android/rules.gni")
+
+  android_library("media_lib") {
+    java_files = [
+      "src/org/domokit/media/MediaPlayerImpl.java",
+      "src/org/domokit/media/MediaServiceImpl.java",
+    ]
+
+    deps = [
+      "//base:base_java",
+      "//mojo/java",
+      "//mojo/public/java:bindings",
+      "//mojo/public/java:system",
+      ":interfaces_java",
+    ]
+  }
+}
diff --git a/services/testing/BUILD.gn b/services/testing/BUILD.gn
index 74b41fbb4ff..880af1a90cb 100644
--- a/services/testing/BUILD.gn
+++ b/services/testing/BUILD.gn
@@ -4,7 +4,7 @@
 
 import("//mojo/public/tools/bindings/mojom.gni")
 
-mojom("testing") {
+mojom("interfaces") {
   sources = [
     "test_harness.mojom",
   ]
diff --git a/shell/BUILD.gn b/shell/BUILD.gn
index c4a0f508f98..a3b7cb4d8be 100644
--- a/shell/BUILD.gn
+++ b/shell/BUILD.gn
@@ -19,7 +19,7 @@ common_deps = [
   "//sky/engine",
   "//sky/engine/tonic",
   "//sky/engine/wtf",
-  "//sky/services/engine",
+  "//sky/services/engine:interfaces",
   "//sky/services/platform",
   "//sky/shell/dart",
   "//ui/gfx/geometry",
@@ -120,7 +120,7 @@ if (is_android) {
       "//services/keyboard",
       "//sky/services/activity:activity_lib",
       "//sky/services/activity:interfaces_java",
-      "//sky/services/engine:engine_java",
+      "//sky/services/engine:interfaces_java",
       "//sky/services/oknet",
     ]
   }
@@ -191,7 +191,7 @@ if (is_android) {
 
     deps = common_deps + [
              ":common",
-             "//sky/services/testing",
+             "//sky/services/testing:interfaces",
            ]
   }
 } else {
diff --git a/tools/skyx.py b/tools/skyx.py
index 094b35abd6d..07fb84fd7fd 100755
--- a/tools/skyx.py
+++ b/tools/skyx.py
@@ -14,6 +14,7 @@ DART_SDK = os.path.join(SRC_ROOT, 'third_party', 'dart-sdk', 'dart-sdk', 'bin')
 
 def main():
     parser = argparse.ArgumentParser(description='Packaging tool for Sky apps')
+    parser.add_argument('--package-root', type=str)
     parser.add_argument('--manifest', type=str)
     parser.add_argument('--asset-base', type=str)
     parser.add_argument('--snapshot', type=str)
@@ -22,6 +23,7 @@ def main():
 
     command = [
         os.path.join(DART_SDK, 'dart'),
+        '--package-root=%s' % args.package_root,
         os.path.join(SKY_TOOLS_DIR, 'skyx', 'bin', 'skyx.dart'),
         '--asset-base', args.asset_base,
         '--snapshot', args.snapshot,
diff --git a/tools/skyx/pubspec.lock b/tools/skyx/pubspec.lock
deleted file mode 100644
index 36d5306871e..00000000000
--- a/tools/skyx/pubspec.lock
+++ /dev/null
@@ -1,35 +0,0 @@
-# Generated by pub
-# See http://pub.dartlang.org/doc/glossary.html#lockfile
-packages:
-  archive:
-    description: archive
-    source: hosted
-    version: "1.0.20"
-  args:
-    description: args
-    source: hosted
-    version: "0.13.2"
-  collection:
-    description: collection
-    source: hosted
-    version: "1.1.1"
-  crypto:
-    description: crypto
-    source: hosted
-    version: "0.9.0"
-  path:
-    description: path
-    source: hosted
-    version: "1.3.5"
-  source_span:
-    description: source_span
-    source: hosted
-    version: "1.1.2"
-  string_scanner:
-    description: string_scanner
-    source: hosted
-    version: "0.1.3+1"
-  yaml:
-    description: yaml
-    source: hosted
-    version: "2.1.3"
diff --git a/tools/tester/BUILD.gn b/tools/tester/BUILD.gn
index d7b02630192..2db5dbe4790 100644
--- a/tools/tester/BUILD.gn
+++ b/tools/tester/BUILD.gn
@@ -26,6 +26,6 @@ mojo_native_application("tester") {
     "//mojo/services/input_events/public/interfaces",
     "//mojo/services/view_manager/public/cpp",
     "//services/window_manager:lib",
-    "//sky/services/testing",
+    "//sky/services/testing:interfaces",
   ]
 }
diff --git a/viewer/BUILD.gn b/viewer/BUILD.gn
index c90e753b331..1dfc6a50c4b 100644
--- a/viewer/BUILD.gn
+++ b/viewer/BUILD.gn
@@ -54,7 +54,7 @@ mojo_native_application("viewer") {
     "//sky/engine/tonic",
     "//sky/services/activity:interfaces",
     "//sky/services/platform",
-    "//sky/services/testing",
+    "//sky/services/testing:interfaces",
     "//sky/shell/dart",
     "//sky/viewer/compositor",
     "//third_party/icu",