Add vector_math and box2d as external Dart packages

mojo/public/dart/rules.gni

 # 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.
 
 # Rules to generate zipped applications for Dart.
 # Rules to generate dart-pkg and dart-pkg/packages.
 
 import("//build/module_args/mojo.gni")
 
 template("dartzip_package") {
@@ skipping 197 matching lines @@
     ]
   }
 }
 
 # Creates a gen/dart-pkg/package_name directory containing symlinks to package
 # sources. Also copies any mojom dependencies into lib/mojom.
 #
 #   sources
 #       List of sources to include in the package.
 #
+#   pkg_dir (optional)
+#       Directory containing the package sources. This overrides sources.
+#
 #   deps (optional)
 #       Note: this can only contain mojom targets.
 #
 #   datadeps (optional)
 #
 #   sdk_ext_directory (optional)
 #       Directory containing sdk-ext .dart sources.
 #
 template("dart_pkg") {
-  pubspec_yaml_path = rebase_path("pubspec.yaml")
+  if (defined(invoker.pkg_dir)) {
+    pubspec_yaml_path = rebase_path("pubspec.yaml", "", invoker.pkg_dir)
+  } else {
+    pubspec_yaml_path = rebase_path("pubspec.yaml")
+  }
   dart_package_name_script =
       rebase_path("mojo/public/tools/dart_package_name.py", ".", mojo_sdk_root)
   package_name = exec_script(dart_package_name_script,
                              [
                                "--pubspec",
                                pubspec_yaml_path,
                              ],
                              "trim string",
                              [ pubspec_yaml_path ])
 
   pkg_directory = rebase_path("$root_gen_dir/dart-pkg")
   package_root = rebase_path("$root_gen_dir/dart-pkg/packages")
   stamp_file = "$root_gen_dir/dart-pkg/${package_name}.stamp"
 
-  assert(defined(invoker.sources))
+  assert(defined(invoker.sources) || defined(invoker.pkg_dir))
 
   action(target_name) {
     deps = []
     if (defined(invoker.deps)) {
       deps += invoker.deps
     }
 
     datadeps = []
     if (defined(invoker.datadeps)) {
       datadeps += invoker.datadeps
@@ skipping 16 matching lines @@
     sdk_ext_directory = []
     if (defined(invoker.sdk_ext_directory)) {
       sdk_ext_directory += [ invoker.sdk_ext_directory ]
     }
 
     script = rebase_path("mojo/public/tools/dart_pkg.py", ".", mojo_sdk_root)
     outputs = [
       stamp_file,
     ]
 
+    if (defined(invoker.sources)) {
+      sources = invoker.sources
+    } else {
+      assert(defined(invoker.pkg_dir))
+      list_script = rebase_path("build/ls.py", ".", mojo_sdk_root)
+      sources = exec_script(list_script,
+                            [
+                              "--target-directory",
+                              rebase_path(invoker.pkg_dir),
+                            ],
+                            "list lines")
+    }
+
     inputs = [
                list_mojoms_script,
                script,
-             ] + rebase_path(invoker.sources)
+             ] + rebase_path(sources)
 
     args = [
              "--package-name",
              package_name,
              "--gen-directory",
              rebase_path("$root_gen_dir/dart-gen"),
              "--pkg-directory",
              pkg_directory,
              "--package-root",
              package_root,
              "--stamp-file",
              rebase_path(stamp_file),
              "--package-sources",
-           ] + rebase_path(invoker.sources) + [ "--mojom-sources" ] +
+           ] + rebase_path(sources) + [ "--mojom-sources" ] +
            rebase_path(mojom_sources, "", mojo_sdk_root) +
            [ "--sdk-ext-directories" ] + rebase_path(sdk_ext_directory)
   }
 }