Fix syntax error in os_macos.cc on iOS.

runtime/vm/os_macos.cc

 // Copyright (c) 2012, 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/globals.h"
 #if defined(TARGET_OS_MACOS)
 
 #include "vm/os.h"
 
 #include <errno.h>  // NOLINT
@@ skipping 124 matching lines @@
 #else
   ASSERT(GetCurrentMonotonicFrequency() == kNanosecondsPerSecond);
   return GetCurrentMonotonicTicks() / kNanosecondsPerMicrosecond;
 #endif  // TARGET_OS_IOS
 }
 
 
 int64_t OS::GetCurrentThreadCPUMicros() {
 #if TARGET_OS_IOS
   // TODO(johnmccutchan): Implement this. No implementation exists in base.
-  return -1
+  return -1;
 #else
   mach_msg_type_number_t count = THREAD_BASIC_INFO_COUNT;
   thread_basic_info_data_t info_data;
   thread_basic_info_t info = &info_data;
   mach_port_t thread_port = mach_thread_self();
   if (thread_port == MACH_PORT_NULL) {
     return -1;
   }
   kern_return_t r = thread_info(thread_port, THREAD_BASIC_INFO,
                                 (thread_info_t)info, &count);
@@ skipping 259 matching lines @@
 }
 
 
 void OS::Exit(int code) {
   exit(code);
 }
 
 }  // namespace dart
 
 #endif  // defined(TARGET_OS_MACOS)