Move mojo and mojom from mojo/public/dart to mojo/dart/packages

mojo/dart/packages/mojo/BUILD.gn

Index: mojo/dart/packages/mojo/BUILD.gn
diff --git a/mojo/dart/packages/mojo/BUILD.gn b/mojo/dart/packages/mojo/BUILD.gn
new file mode 100644
index 0000000000000000000000000000000000000000..ba3d238bca9e8d5dc30899a4d3840d8a5faa3329
--- /dev/null
+++ b/mojo/dart/packages/mojo/BUILD.gn
@@ -0,0 +1,26 @@
+# Copyright 2015 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("//mojo/public/mojo_sdk.gni")
+import("//mojo/public/dart/rules.gni")
+
+import("sources.gni")
+import("sdk_ext_sources.gni")
+
+dart_pkg("mojo") {
+  libs = package_mojo_entrypoints
+  sources = package_mojo_sources + [
+              "lib/_sdkext",
+              "pubspec.yaml",
+              "CHANGELOG.md",
+              "README.md",
+            ]
+
+  sdk_ext_files = dart_mojo_internal_sdk_sources
+
+  deps = [
+    "//mojo/public/dart/third_party",
+    "//mojo/public/interfaces",
+  ]
+}