Revert of Update mojo sdk to rev c02a28868825edfa57ab77947b8cb15e741c5598

third_party/mojo/src/mojo/edk/system/incoming_endpoint.h

Index: third_party/mojo/src/mojo/edk/system/incoming_endpoint.h
diff --git a/third_party/mojo/src/mojo/edk/system/incoming_endpoint.h b/third_party/mojo/src/mojo/edk/system/incoming_endpoint.h
index bf0acf34dfef0b530d1b2a85b961402d92afecfa..22bf0b9437079e276a1bcb7d935ed5777959130b 100644
--- a/third_party/mojo/src/mojo/edk/system/incoming_endpoint.h
+++ b/third_party/mojo/src/mojo/edk/system/incoming_endpoint.h
@@ -8,9 +8,9 @@
 #include <stddef.h>
 
 #include "base/memory/ref_counted.h"
+#include "base/synchronization/lock.h"
 #include "mojo/edk/system/channel_endpoint_client.h"
 #include "mojo/edk/system/message_in_transit_queue.h"
-#include "mojo/edk/system/mutex.h"
 #include "mojo/edk/system/system_impl_export.h"
 #include "mojo/public/cpp/system/macros.h"
 
@@ -32,7 +32,7 @@
   IncomingEndpoint();
 
   // Must be called before any other method.
-  scoped_refptr<ChannelEndpoint> Init() MOJO_NOT_THREAD_SAFE;
+  scoped_refptr<ChannelEndpoint> Init();
 
   scoped_refptr<MessagePipe> ConvertToMessagePipe();
   scoped_refptr<DataPipe> ConvertToDataPipeProducer(
@@ -52,9 +52,9 @@
  private:
   ~IncomingEndpoint() override;
 
-  Mutex mutex_;
-  scoped_refptr<ChannelEndpoint> endpoint_ MOJO_GUARDED_BY(mutex_);
-  MessageInTransitQueue message_queue_ MOJO_GUARDED_BY(mutex_);
+  base::Lock lock_;  // Protects the following members.
+  scoped_refptr<ChannelEndpoint> endpoint_;
+  MessageInTransitQueue message_queue_;
 
   MOJO_DISALLOW_COPY_AND_ASSIGN(IncomingEndpoint);
 };