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

mojo/edk/system/slave_connection_manager.h

Index: mojo/edk/system/slave_connection_manager.h
diff --git a/mojo/edk/system/slave_connection_manager.h b/mojo/edk/system/slave_connection_manager.h
index 86876bb5d0c0d84b4ee605b3e7eef11cf6f46638..bd66534c91e9464c0a2abfdcd89910356af3b110 100644
--- a/mojo/edk/system/slave_connection_manager.h
+++ b/mojo/edk/system/slave_connection_manager.h
@@ -13,9 +13,9 @@
 #include "mojo/edk/embedder/scoped_platform_handle.h"
 #include "mojo/edk/embedder/slave_process_delegate.h"
 #include "mojo/edk/system/connection_manager.h"
-#include "mojo/edk/system/mutex.h"
 #include "mojo/edk/system/raw_channel.h"
 #include "mojo/edk/system/waitable_event.h"
+#include "mojo/edk/util/mutex.h"
 #include "mojo/public/cpp/system/macros.h"
 
 namespace base {
@@ -146,7 +146,7 @@ class SlaveConnectionManager final : public ConnectionManager,
   //
   // TODO(vtl): This is all a hack. It'd really suffice to have a version of
   // |RawChannel| with fully synchronous reading and writing.
-  Mutex mutex_;
+  util::Mutex mutex_;
   AutoResetWaitableEvent event_;
 
   MOJO_DISALLOW_COPY_AND_ASSIGN(SlaveConnectionManager);