VM: Re-format to use at most one newline between functions

runtime/vm/os_thread_macos.h

Index: runtime/vm/os_thread_macos.h
diff --git a/runtime/vm/os_thread_macos.h b/runtime/vm/os_thread_macos.h
index 2a2fcf5be10339b52c8411491db62713edba3957..9b053d0a32b4a413aa4bbd44cde93be20b6aa52a 100644
--- a/runtime/vm/os_thread_macos.h
+++ b/runtime/vm/os_thread_macos.h
@@ -20,11 +20,9 @@ typedef pthread_key_t ThreadLocalKey;
 typedef pthread_t ThreadId;
 typedef pthread_t ThreadJoinId;
 
-
 static const ThreadLocalKey kUnsetThreadLocalKey =
     static_cast<pthread_key_t>(-1);
 
-
 class ThreadInlineImpl {
  private:
   ThreadInlineImpl() {}
@@ -42,7 +40,6 @@ class ThreadInlineImpl {
   DISALLOW_COPY_AND_ASSIGN(ThreadInlineImpl);
 };
 
-
 class MutexData {
  private:
   MutexData() {}
@@ -58,7 +55,6 @@ class MutexData {
   DISALLOW_COPY_AND_ASSIGN(MutexData);
 };
 
-
 class MonitorData {
  private:
   MonitorData() {}