Fix Dartium build:

runtime/bin/thread_linux.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 "platform/globals.h"
 #if defined(TARGET_OS_LINUX)
 
 #include "bin/thread.h"
 
 #include <errno.h>  // NOLINT
@@ skipping 160 matching lines @@
   ASSERT(thread_id == GetCurrentThreadId());
   ASSERT(cpu_usage != NULL);
   struct timespec ts;
   int r = clock_gettime(CLOCK_THREAD_CPUTIME_ID, &ts);
   ASSERT(r == 0);
   *cpu_usage = (ts.tv_sec * kNanosecondsPerSecond + ts.tv_nsec) /
                kNanosecondsPerMicrosecond;
 }
 
 
+void Thread::InitOnce() {
+  // Nothing to be done.
+}
+
+
 Mutex::Mutex() {
   pthread_mutexattr_t attr;
   int result = pthread_mutexattr_init(&attr);
   VALIDATE_PTHREAD_RESULT(result);
 
 #if defined(DEBUG)
   result = pthread_mutexattr_settype(&attr, PTHREAD_MUTEX_ERRORCHECK);
   VALIDATE_PTHREAD_RESULT(result);
 #endif  // defined(DEBUG)
 
@@ skipping 132 matching lines @@
 void Monitor::NotifyAll() {
   // TODO(iposva): Do we need to track lock owners?
   int result = pthread_cond_broadcast(data_.cond());
   VALIDATE_PTHREAD_RESULT(result);
 }
 
 }  // namespace bin
 }  // namespace dart
 
 #endif  // defined(TARGET_OS_LINUX)