Fix the build.

runtime/vm/json_stream.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 "platform/assert.h"
 
 #include "vm/dart_entry.h"
 #include "vm/debugger.h"
 #include "vm/json_stream.h"
 #include "vm/message.h"
@@ skipping 263 matching lines @@
 
 
 void JSONStream::PrintProperty(const char* name, intptr_t i) {
   ASSERT(Utils::IsJavascriptInt(i));
   PrintPropertyName(name);
   PrintValue(i);
 }
 
 
 void JSONStream::PrintProperty64(const char* name, int64_t i) {
-  ASSERT(Utils::IsJavascriptInt(i));
+  ASSERT(Utils::IsJavascriptInt64(i));
   PrintPropertyName(name);
   PrintValue64(i);
 }
 
 
 void JSONStream::PrintProperty(const char* name, double d) {
   PrintPropertyName(name);
   PrintValue(d);
 }
 
@@ skipping 190 matching lines @@
   intptr_t len2 = OS::VSNPrint(p, len+1, format, args);
   va_end(args);
   ASSERT(len == len2);
   stream_->buffer_.AddChar('"');
   stream_->AddEscapedUTF8String(p);
   stream_->buffer_.AddChar('"');
   free(p);
 }
 
 }  // namespace dart