Add support for compression filters in the mojo dart:io

mojo/dart/embedder/common.h

 // 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.
 
 #ifndef MOJO_DART_EMBEDDER_COMMON_H_
 #define MOJO_DART_EMBEDDER_COMMON_H_
 
 #include "dart/runtime/include/dart_api.h"
 
 namespace mojo {
 namespace dart {
 
 class DartEmbedder {
  public:
+  static Dart_Handle GetDartType(const char* library_url,
+                                 const char* class_name);
+
+  static Dart_Handle NewDartExceptionWithMessage(const char* library_url,
+                                                 const char* error_type,
+                                                 const char* message);
+
+  static Dart_Handle NewInternalError(const char* message);
+
   // Returns the integer value of a Dart object. If the object is not
   // an integer value an API error is propagated.
   static int64_t GetIntegerValue(Dart_Handle value_obj);
   // Returns the integer value of a Dart object. If the object is not
   // an integer value or outside the requested range an API error is
   // propagated.
   static int64_t GetInt64ValueCheckRange(
       Dart_Handle value_obj, int64_t lower, int64_t upper);
   // Returns the intptr_t value of a Dart object. If the object is not
   // an integer value or the value is outside the intptr_t range an
@@ skipping 38 matching lines @@
   // Creates a Uint8List with a copy of bytes.
   // Any error is propagated.
   static Dart_Handle MakeUint8TypedData(uint8_t* bytes, intptr_t length);
 };
 
 }  // namespace dart
 }  // namespace mojo
 
 
 #endif  // MOJO_DART_EMBEDDER_COMMON_H_