[mojo-edk] Add MojoWatch and MojoCancelWatch APIs

mojo/edk/system/data_pipe_consumer_dispatcher.h

Index: mojo/edk/system/data_pipe_consumer_dispatcher.h
diff --git a/mojo/edk/system/data_pipe_consumer_dispatcher.h b/mojo/edk/system/data_pipe_consumer_dispatcher.h
index c75833bbf85e7ec6ead0d961622452c9a4d96db1..55c45d0e3846636b4b921e52a5627919563f81af 100644
--- a/mojo/edk/system/data_pipe_consumer_dispatcher.h
+++ b/mojo/edk/system/data_pipe_consumer_dispatcher.h
@@ -42,7 +42,7 @@ class MOJO_SYSTEM_IMPL_EXPORT DataPipeConsumerDispatcher final
 
   // Dispatcher:
   Type GetType() const override;
-  MojoResult Close() override;
+  MojoResult Close(RequestContext* request_context) override;
   MojoResult ReadData(void* elements,
                       uint32_t* num_bytes,
                       MojoReadDataFlags flags) override;
@@ -63,9 +63,9 @@ class MOJO_SYSTEM_IMPL_EXPORT DataPipeConsumerDispatcher final
   bool EndSerialize(void* destination,
                     ports::PortName* ports,
                     PlatformHandle* handles) override;
-  bool BeginTransit() override;
-  void CompleteTransitAndClose() override;
-  void CancelTransit() override;
+  bool BeginTransit(RequestContext* request_context) override;
+  void CompleteTransitAndClose(RequestContext* request_context) override;
+  void CancelTransit(RequestContext* request_context) override;
 
   static scoped_refptr<DataPipeConsumerDispatcher>
   Deserialize(const void* data,