EDK: Move mutex.*, cond_var.*, and thread_annotations.h to //mojo/edk/util.

mojo/edk/util/mutex.h

Index: mojo/edk/util/mutex.h
diff --git a/mojo/edk/system/mutex.h b/mojo/edk/util/mutex.h
similarity index 90%
rename from mojo/edk/system/mutex.h
rename to mojo/edk/util/mutex.h
index 0ce1ed396c6a237075cb2db7d76cecdcc807ef58..381ce7adc72b92c3506d009d3787e0ec7ca8271a 100644
--- a/mojo/edk/system/mutex.h
+++ b/mojo/edk/util/mutex.h
@@ -6,22 +6,21 @@
 //
 // TODO(vtl): Add support for non-exclusive (reader) locks.
 
-#ifndef MOJO_EDK_SYSTEM_MUTEX_H_
-#define MOJO_EDK_SYSTEM_MUTEX_H_
+#ifndef MOJO_EDK_UTIL_MUTEX_H_
+#define MOJO_EDK_UTIL_MUTEX_H_
 
 #include <pthread.h>
 
-#include "mojo/edk/system/thread_annotations.h"
+#include "mojo/edk/util/thread_annotations.h"
 #include "mojo/public/cpp/system/macros.h"
 
 namespace mojo {
-namespace system {
-
-// So |Mutex| can friend it.
-class CondVar;
+namespace util {
 
 // Mutex -----------------------------------------------------------------------
 
+class CondVar;
+
 class MOJO_LOCKABLE Mutex {
  public:
 #if defined(NDEBUG) && !defined(DCHECK_ALWAYS_ON)
@@ -78,7 +77,7 @@ class MOJO_SCOPED_LOCKABLE MutexLocker {
   MOJO_DISALLOW_COPY_AND_ASSIGN(MutexLocker);
 };
 
-}  // namespace system
+}  // namespace util
 }  // namespace mojo
 
-#endif  // MOJO_EDK_SYSTEM_MUTEX_H_
+#endif  // MOJO_EDK_UTIL_MUTEX_H_