Move symbol table from per isolate snapshot to vm isolate snapshot, this reduces the per isolate in…

runtime/vm/service.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.
 
 #include "vm/service.h"
 
 #include "include/dart_api.h"
 #include "platform/globals.h"
 
 #include "vm/compiler.h"
@@ skipping 1254 matching lines @@
     uword message_id = 0;
     if (GetUnsignedIntegerId(rest, &message_id, 16)) {
       MessageHandler::AcquiredQueues aq;
       isolate->message_handler()->AcquireQueues(&aq);
       Message* message = aq.queue()->FindMessageById(message_id);
       if (message == NULL) {
         printf("Could not find message %" Px "\n", message_id);
         // Not found.
         return false;
       }
-      SnapshotReader reader(message->data(),
-                            message->len(),
-                            Snapshot::kMessage,
-                            isolate,
-                            isolate->current_zone());
+      MessageSnapshotReader reader(message->data(),
+                                   message->len(),
+                                   isolate,
+                                   isolate->current_zone());
       const Object& msg_obj = Object::Handle(reader.ReadObject());
       msg_obj.PrintJSON(js);
       return true;
     } else {
       printf("Could not get id from %s\n", rest);
     }
   }
   return false;
 }
 
@@ skipping 1408 matching lines @@
     ServiceMethodDescriptor& method = service_methods_[i];
     if (strcmp(method_name, method.name) == 0) {
       return &method;
     }
   }
   return NULL;
 }
 
 
 }  // namespace dart