Make VM service id handling JSON-RPC 2 compliant.

runtime/vm/service_test.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/globals.h"
 
 #include "include/dart_tools_api.h"
 #include "vm/dart_api_impl.h"
 #include "vm/dart_entry.h"
 #include "vm/debugger.h"
@@ skipping 512 matching lines @@
 
   // Build a mock message handler and wrap it in a dart port.
   ServiceTestMessageHandler handler;
   Dart_Port port_id = PortMap::CreatePort(&handler);
   Dart_Handle port = Api::NewHandle(isolate, SendPort::New(port_id));
   EXPECT_VALID(port);
   EXPECT_VALID(Dart_SetField(lib, NewString("port"), port));
 
 
   Array& service_msg = Array::Handle();
-  service_msg = Eval(lib, "[0, port, '0', 'alpha', [], []]");
+  service_msg = Eval(lib, "[0, port, '\"', 'alpha', [], []]");
   Service::HandleRootMessage(service_msg);
   handler.HandleNextMessage();
-  EXPECT_STREQ("{\"jsonrpc\":\"2.0\", \"result\":alpha, \"id\":\"0\"}",
+  EXPECT_STREQ("{\"jsonrpc\":\"2.0\", \"result\":alpha, \"id\":\"\\\"\"}",
                handler.msg());
-  service_msg = Eval(lib, "[0, port, '0', 'beta', [], []]");
+  service_msg = Eval(lib, "[0, port, 1, 'beta', [], []]");
   Service::HandleRootMessage(service_msg);
   handler.HandleNextMessage();
-  EXPECT_STREQ("{\"jsonrpc\":\"2.0\", \"result\":beta, \"id\":\"0\"}",
+  EXPECT_STREQ("{\"jsonrpc\":\"2.0\", \"result\":beta, \"id\":1}",
                handler.msg());
 }
 
 
 TEST_CASE(Service_EmbedderIsolateHandler) {
   const char* kScript =
     "var port;\n"  // Set to our mock port by C++.
     "\n"
     "var x = 7;\n"
     "main() {\n"
@@ skipping 74 matching lines @@
       Eval(lib, "[0, port, '0', '_getCpuProfile', ['tags'], ['Bogus']]");
   Service::HandleIsolateMessage(isolate, service_msg);
   handler.HandleNextMessage();
   // Expect error.
   EXPECT_SUBSTRING("\"error\"", handler.msg());
 }
 
 #endif  // !defined(TARGET_ARCH_ARM64)
 
 }  // namespace dart