Stop running pub get at gclient sync time and fix build bugs

mojo/public/dart/third_party/mime/lib/src/magic_number.dart

+// Copyright (c) 2013, the Dart project authors.  Please see the AUTHORS file
+// for details. All rights reserved. Use of this source code is governed by a
+// BSD-style license that can be found in the LICENSE file.
+
+library mime.magic_number;
+
+class MagicNumber {
+  final String mimeType;
+  final List<int> numbers;
+  final List<int> mask;
+
+  const MagicNumber(this.mimeType, this.numbers, {this.mask});
+
+  bool matches(List<int> header) {
+    if (header.length < numbers.length) return false;
+
+    for (int i = 0; i < numbers.length; i++) {
+      if (mask != null) {
+        if ((mask[i] & numbers[i]) != (mask[i] & header[i])) return false;
+      } else {
+        if (numbers[i] != header[i]) return false;
+      }
+    }
+
+    return true;
+  }
+
+}
+
+const int DEFAULT_MAGIC_NUMBERS_MAX_LENGTH = 12;
+
+const List<MagicNumber> DEFAULT_MAGIC_NUMBERS = const [
+  const MagicNumber('application/pdf', const [0x25, 0x50, 0x44, 0x46]),
+  const MagicNumber('application/postscript', const [0x25, 0x51]),
+  const MagicNumber('image/gif', const [0x47, 0x49, 0x46, 0x38, 0x37, 0x61]),
+  const MagicNumber('image/gif', const [0x47, 0x49, 0x46, 0x38, 0x39, 0x61]),
+  const MagicNumber('image/jpeg', const [0xFF, 0xD8]),
+  const MagicNumber('image/png',
+      const [0x89, 0x50, 0x4E, 0x47, 0x0D, 0x0A, 0x1A, 0x0A]),
+  const MagicNumber('image/tiff', const [0x49, 0x49, 0x2A, 0x00]),
+  const MagicNumber('image/tiff', const [0x4D, 0x4D, 0x00, 0x2A]),
+  const MagicNumber(
+      'video/mp4',
+      const [0x00, 0x00, 0x00, 0x00, 0x66, 0x74,
+             0x79, 0x70, 0x33, 0x67, 0x70, 0x35],
+      mask: const [0xFF, 0xFF, 0xFF, 0x00, 0xFF, 0xFF,
+                   0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF])
+];