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

mojo/dart/packages/mojom/lib/src/generate.dart

 // 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.
 
 /// This library generates Mojo bindings for a Dart package.
 
 library generate;
 
 import 'dart:async';
 import 'dart:convert';
@@ skipping 394 matching lines @@
             '\t$dart $packRoot $scriptPath single -m $mojoSdk -r $root '
             '-p $packagePath $skips');
         _errors++;
         return;
       }
     }
   }
 
   bool _shouldSkip(File f) => containsPrefix(f.path, _skip);
 }