Make GlobalDescriptors::MaybeGet return -1 when the key is not found.

ipc/ipc_fuzzing_tests.cc

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include <stdio.h>
 #include <string>
 #include <sstream>
 
 #include "base/message_loop.h"
 #include "base/process_util.h"
@@ skipping 228 matching lines @@
     if (FUZZER_ROUTING_ID != last_msg_->routing_id())
       return false;
     return (type_id == last_msg_->type());
   };
 
   IPC::Message* last_msg_;
 };
 
 // Runs the fuzzing server child mode. Returns when the preset number
 // of messages have been received.
-MULTIPROCESS_TEST_MAIN(RunFuzzServer) {
+MULTIPROCESS_IPC_TEST_MAIN(RunFuzzServer) {
   MessageLoopForIO main_message_loop;
   FuzzerServerListener listener;
   IPC::Channel chan(kFuzzerChannel, IPC::Channel::MODE_CLIENT, &listener);
   CHECK(chan.Connect());
   listener.Init(&chan);
   MessageLoop::current()->Run();
   return 0;
 }
 
 class IPCFuzzingTest : public IPCChannelTest {
@@ skipping 147 matching lines @@
   msg = new IPC::Message(MSG_ROUTING_CONTROL, MsgClassIS::ID,
                          IPC::Message::PRIORITY_NORMAL);
   msg->WriteInt(0x64);
   msg->WriteInt(0x32);
   EXPECT_FALSE(server.OnMessageReceived(*msg));
   delete msg;
 
   EXPECT_EQ(0, server.unhandled_msgs());
 #endif
 }