Reload native extensions when starting from a snapshot.

runtime/bin/dartutils.h

 // Copyright (c) 2012, 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.
 
 #ifndef RUNTIME_BIN_DARTUTILS_H_
 #define RUNTIME_BIN_DARTUTILS_H_
 
 #include "bin/isolate_data.h"
 #include "include/dart_api.h"
 #include "include/dart_native_api.h"
@@ skipping 107 matching lines @@
                                      int64_t val);
   static Dart_Handle SetStringField(Dart_Handle handle,
                                     const char* name,
                                     const char* val);
   static bool IsDartSchemeURL(const char* url_name);
   static bool IsDartExtensionSchemeURL(const char* url_name);
   static bool IsDartIOLibURL(const char* url_name);
   static bool IsDartBuiltinLibURL(const char* url_name);
   static bool IsHttpSchemeURL(const char* url_name);
   static const char* RemoveScheme(const char* url);
+  static char* RemoveFilename(const char* url);

[siva, 2016/11/02 23:48:38]

Would File::DirName be a more appropriate implementation instead
of RemoveFilename here?

[Cutch, 2016/11/03 17:45:34]

+1.

   static void* MapExecutable(const char* name, intptr_t* file_len);
   static void* OpenFile(const char* name, bool write);
   static void ReadFile(const uint8_t** data, intptr_t* file_len, void* stream);
   static void WriteFile(const void* buffer, intptr_t num_bytes, void* stream);
   static void CloseFile(void* stream);
   static bool EntropySource(uint8_t* buffer, intptr_t length);
   static Dart_Handle ReadStringFromFile(const char* filename);
   static Dart_Handle MakeUint8Array(const uint8_t* buffer, intptr_t length);
   static Dart_Handle LibraryTagHandler(Dart_LibraryTag tag,
                                        Dart_Handle library,
@@ skipping 542 matching lines @@
   bool is_typed_data_;
 
   DISALLOW_ALLOCATION();
   DISALLOW_COPY_AND_ASSIGN(ScopedMemBuffer);
 };
 
 }  // namespace bin
 }  // namespace dart
 
 #endif  // RUNTIME_BIN_DARTUTILS_H_