Rationalize Dart mojo and sky package structure

mojo/public/dart/src/buffer.dart

-// 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.
-
-part of core;
-
-class MojoSharedBuffer {
-  static const int CREATE_FLAG_NONE = 0;
-  static const int DUPLICATE_FLAG_NONE = 0;
-  static const int MAP_FLAG_NONE = 0;
-
-  MojoHandle handle;
-  MojoResult status;
-  ByteData mapping;
-
-  MojoSharedBuffer(this.handle,
-      [this.status = MojoResult.OK, this.mapping = null]);
-
-  factory MojoSharedBuffer.create(int numBytes, [int flags = 0]) {
-    List result = MojoSharedBufferNatives.Create(numBytes, flags);
-    if (result == null) {
-      return null;
-    }
-    assert((result is List) && (result.length == 2));
-    var r = new MojoResult(result[0]);
-    if (!r.isOk) {
-      return null;
-    }
-
-    MojoSharedBuffer buf =
-        new MojoSharedBuffer(new MojoHandle(result[1]), r, null);
-    return buf;
-  }
-
-  factory MojoSharedBuffer.duplicate(MojoSharedBuffer msb, [int flags = 0]) {
-    List result = MojoSharedBufferNatives.Duplicate(msb.handle.h, flags);
-    if (result == null) {
-      return null;
-    }
-    assert((result is List) && (result.length == 2));
-    var r = new MojoResult(result[0]);
-    if (!r.isOk) {
-      return null;
-    }
-
-    MojoSharedBuffer dupe =
-        new MojoSharedBuffer(new MojoHandle(result[1]), r, null);
-    return dupe;
-  }
-
-  MojoResult close() {
-    if (handle == null) {
-      status = MojoResult.INVALID_ARGUMENT;
-      return status;
-    }
-    MojoResult r = handle.close();
-    status = r;
-    mapping = null;
-    return status;
-  }
-
-  MojoResult map(int offset, int numBytes, [int flags = 0]) {
-    if (handle == null) {
-      status = MojoResult.INVALID_ARGUMENT;
-      return status;
-    }
-    List result =
-        MojoSharedBufferNatives.Map(this, handle.h, offset, numBytes, flags);
-    if (result == null) {
-      status = MojoResult.INVALID_ARGUMENT;
-      return status;
-    }
-    assert((result is List) && (result.length == 2));
-    status = new MojoResult(result[0]);
-    mapping = result[1];
-    return status;
-  }
-
-  MojoResult unmap() {
-    int r = MojoSharedBufferNatives.Unmap(mapping);
-    status = new MojoResult(r);
-    mapping = null;
-    return status;
-  }
-}