Remove usage of deprecated APIs from v8 itself

src/mksnapshot.cc

 // Copyright 2006-2008 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 314 matching lines @@
     chars[size] = '\0';
     for (int i = 0; i < size;) {
       int read = static_cast<int>(fread(&chars[i], 1, size - i, file));
       if (read < 0) {
         fprintf(stderr, "Failed to read '%s': errno %d\n", name, errno);
         exit(1);
       }
       i += read;
     }
     fclose(file);
-    Local<String> source = String::New(chars);
+    Local<String> source = String::NewFromUtf8(isolate, chars);
     TryCatch try_catch;
     Local<Script> script = Script::Compile(source);
     if (try_catch.HasCaught()) {
       fprintf(stderr, "Failure compiling '%s'\n", name);
       DumpException(try_catch.Message());
       exit(1);
     }
     script->Run();
     if (try_catch.HasCaught()) {
       fprintf(stderr, "Failure running '%s'\n", name);
       DumpException(try_catch.Message());
       exit(1);
     }
   }
   // Make sure all builtin scripts are cached.
   { HandleScope scope(isolate);
     for (int i = 0; i < i::Natives::GetBuiltinsCount(); i++) {
       internal_isolate->bootstrapper()->NativesSourceLookup(i);
     }
   }
   // If we don't do this then we end up with a stray root pointing at the
   // context even after we have disposed of the context.
   internal_isolate->heap()->CollectAllGarbage(
       i::Heap::kNoGCFlags, "mksnapshot");
   i::Object* raw_context = *v8::Utils::OpenPersistent(context);
-  context.Dispose();
+  context.Reset();
   CppByteSink sink(argv[1]);
   // This results in a somewhat smaller snapshot, probably because it gets rid
   // of some things that are cached between garbage collections.
   i::StartupSerializer ser(internal_isolate, &sink);
   ser.SerializeStrongReferences();
 
   i::PartialSerializer partial_ser(
       internal_isolate, &ser, sink.partial_sink());
   partial_ser.Serialize(&raw_context);
 
@@ skipping 22 matching lines @@
       "",
       ser.CurrentAllocationAddress(i::NEW_SPACE),
       ser.CurrentAllocationAddress(i::OLD_POINTER_SPACE),
       ser.CurrentAllocationAddress(i::OLD_DATA_SPACE),
       ser.CurrentAllocationAddress(i::CODE_SPACE),
       ser.CurrentAllocationAddress(i::MAP_SPACE),
       ser.CurrentAllocationAddress(i::CELL_SPACE),
       ser.CurrentAllocationAddress(i::PROPERTY_CELL_SPACE));
   return 0;
 }