Check in generated Dart bindings and add presubmit script

mojo/public/tools/bindings/generators/mojom_dart_generator.py

 # 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.
 
 """Generates dart source files from a mojom.Module."""
 
 import os
 import re
 import shutil
 import sys
@@ skipping 428 matching lines @@
 
   @UseJinja("dart_templates/module.lib.tmpl", filters=dart_filters)
   def GenerateLibModule(self, args):
     return self.GetParameters(args)
 
 
   def GenerateFiles(self, args):
     elements = self.module.namespace.split('.')
     elements.append("%s.dart" % self.module.name)
 
+    lib_module = self.GenerateLibModule(args)
+
+    # List of packages with checked in bindings.
+    # TODO(johnmccutchan): Stop generating bindings as part of build system
+    # and then remove this.
+    packages_with_checked_in_bindings = [
+      'mojo',
+      'mojo_apptest',
+      'mojo_services',
+      'mojo_sdk'
+      'mojom'
+    ]
     package_name = GetPackage(self.module)
-    lib_module = self.GenerateLibModule(args)
-    pkg_path = os.path.join("dart-pkg", package_name, "lib", *elements)
-    self.Write(lib_module, pkg_path)
+    if not (package_name in packages_with_checked_in_bindings):
+      pkg_path = os.path.join("dart-pkg", package_name, "lib", *elements)
+      self.Write(lib_module, pkg_path)
 
     gen_path = os.path.join("dart-gen", package_name, "lib", *elements)
     full_gen_path = os.path.join(self.output_dir, gen_path)
     self.Write(lib_module, gen_path)
 
     link = self.MatchMojomFilePath("%s.dart" % self.module.name)
     full_link_path = os.path.join(self.output_dir, link)
     if os.path.exists(full_link_path):
       os.unlink(full_link_path)
     fileutil.EnsureDirectoryExists(os.path.dirname(full_link_path))
@@ skipping 37 matching lines @@
         interface_to_import[name] = each_import["unique_name"] + "." + name
     return interface_to_import
 
   def ImportedFrom(self):
     interface_to_import = {}
     for each_import in self.module.imports:
       for each_interface in each_import["module"].interfaces:
         name = each_interface.name
         interface_to_import[name] = each_import["unique_name"] + "."
     return interface_to_import