Revert "Hide Isolate pointer from embedder"

runtime/bin/gen_snapshot.cc

 // 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.
 
 // Generate a snapshot file after loading all the scripts specified on the
 // command line.
 
 #include <stdlib.h>
 #include <string.h>
 #include <stdio.h>
@@ skipping 153 matching lines @@
   if (!file->WriteFully(buffer, size)) {
     Log::PrintErr("Error: Failed to write snapshot file.\n\n");
   }
   delete file;
 }
 
 
 class UriResolverIsolateScope {
  public:
   UriResolverIsolateScope() {
-    ASSERT(isolate != DART_ILLEGAL_ISOLATE);
+    ASSERT(isolate != NULL);
     snapshotted_isolate_ = Dart_CurrentIsolate();
     Dart_ExitIsolate();
     Dart_EnterIsolate(isolate);
     Dart_EnterScope();
   }
 
   ~UriResolverIsolateScope() {
-    ASSERT(snapshotted_isolate_ != DART_ILLEGAL_ISOLATE);
+    ASSERT(snapshotted_isolate_ != NULL);
     Dart_ExitScope();
     Dart_ExitIsolate();
     Dart_EnterIsolate(snapshotted_isolate_);
   }
 
   static Dart_Isolate isolate;
 
  private:
   Dart_Isolate snapshotted_isolate_;
 
   DISALLOW_COPY_AND_ASSIGN(UriResolverIsolateScope);
 };
 
-Dart_Isolate UriResolverIsolateScope::isolate = DART_ILLEGAL_ISOLATE;
+Dart_Isolate UriResolverIsolateScope::isolate = NULL;
 
 
 static Dart_Handle ResolveUriInWorkingDirectory(const char* script_uri) {
   bool failed = false;
   char* result_string = NULL;
 
   {
     UriResolverIsolateScope scope;
 
     // Run DartUtils::ResolveUriInWorkingDirectory in context of uri resolver
@@ skipping 338 matching lines @@
                        DartUtils::ReadFile,
                        DartUtils::WriteFile,
                        DartUtils::CloseFile,
                        DartUtils::EntropySource)) {
     Log::PrintErr("VM initialization failed\n");
     return 255;
   }
 
   char* error;
   Dart_Isolate isolate = Dart_CreateIsolate(NULL, NULL, NULL, NULL, &error);
-  if (isolate == DART_ILLEGAL_ISOLATE) {
+  if (isolate == NULL) {
     Log::PrintErr("Error: %s", error);
     free(error);
     exit(255);
   }
 
   Dart_Handle result;
   Dart_Handle library;
   Dart_EnterScope();
 
   ASSERT(vm_isolate_snapshot_filename != NULL);
@@ skipping 24 matching lines @@
                                            false,
                                            builtin_lib);
     CHECK_RESULT(result);
     Dart_ExitScope();
     Dart_ExitIsolate();
 
     UriResolverIsolateScope::isolate = isolate;
 
     // Now we create an isolate into which we load all the code that needs to
     // be in the snapshot.
-    if (Dart_CreateIsolate(
-        NULL, NULL, NULL, NULL, &error) == DART_ILLEGAL_ISOLATE) {
+    if (Dart_CreateIsolate(NULL, NULL, NULL, NULL, &error) == NULL) {
       fprintf(stderr, "%s", error);
       free(error);
       exit(255);
     }
     Dart_EnterScope();
 
     // Set up the library tag handler in such a manner that it will use the
     // URL mapping specified on the command line to load the libraries.
     result = Dart_SetLibraryTagHandler(CreateSnapshotLibraryTagHandler);
     CHECK_RESULT(result);
@@ skipping 13 matching lines @@
   }
   return 0;
 }
 
 }  // namespace bin
 }  // namespace dart
 
 int main(int argc, char** argv) {
   return dart::bin::main(argc, argv);
 }