Don't call the other wait set impl dispatcher methods under mutex either.

mojo/edk/system/wait_set_dispatcher.h

Index: mojo/edk/system/wait_set_dispatcher.h
diff --git a/mojo/edk/system/wait_set_dispatcher.h b/mojo/edk/system/wait_set_dispatcher.h
index dd4e96e5ef1cbd8455c63c7f2d8845bb1e95a7bd..2dad87523c3aebb8baf2b7bbacd25a8050a8b332 100644
--- a/mojo/edk/system/wait_set_dispatcher.h
+++ b/mojo/edk/system/wait_set_dispatcher.h
@@ -54,12 +54,11 @@ class WaitSetDispatcher final : public Dispatcher {
   util::RefPtr<Dispatcher> CreateEquivalentDispatcherAndCloseImplNoLock(
       MessagePipe* message_pipe,
       unsigned port) override;
-  MojoResult WaitSetAddImplNoLock(
-      UserPointer<const MojoWaitSetAddOptions> options,
-      Handle&& handle,
-      MojoHandleSignals signals,
-      uint64_t cookie) override;
-  MojoResult WaitSetRemoveImplNoLock(uint64_t cookie) override;
+  MojoResult WaitSetAddImpl(UserPointer<const MojoWaitSetAddOptions> options,
+                            Handle&& handle,
+                            MojoHandleSignals signals,
+                            uint64_t cookie) override;
+  MojoResult WaitSetRemoveImpl(uint64_t cookie) override;
   MojoResult WaitSetWaitImpl(MojoDeadline deadline,
                              UserPointer<uint32_t> num_results,
                              UserPointer<MojoWaitSetResult> results,