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

mojo/edk/system/waiter.h

Index: mojo/edk/system/waiter.h
diff --git a/mojo/edk/system/waiter.h b/mojo/edk/system/waiter.h
index 39c28d9d4352dda1550c203385cb3cb744df3a21..0a2f7ee65178d565735250c8d8ebd618d39fe7fb 100644
--- a/mojo/edk/system/waiter.h
+++ b/mojo/edk/system/waiter.h
@@ -8,9 +8,9 @@
 #include <stdint.h>
 
 #include "mojo/edk/system/awakable.h"
-#include "mojo/edk/system/cond_var.h"
-#include "mojo/edk/system/mutex.h"
-#include "mojo/edk/system/thread_annotations.h"
+#include "mojo/edk/util/cond_var.h"
+#include "mojo/edk/util/mutex.h"
+#include "mojo/edk/util/thread_annotations.h"
 #include "mojo/public/c/system/types.h"
 #include "mojo/public/cpp/system/macros.h"
 
@@ -61,8 +61,8 @@ class Waiter final : public Awakable {
   bool Awake(MojoResult result, uintptr_t context) override;
 
  private:
-  CondVar cv_;  // Associated to |mutex_|.
-  Mutex mutex_;
+  util::CondVar cv_;  // Associated to |mutex_|.
+  util::Mutex mutex_;
 #ifndef NDEBUG
   bool initialized_ MOJO_GUARDED_BY(mutex_);
 #endif