Make it possible to remove an Awakable with a specific "context" from a Dispatcher.

mojo/edk/system/data_pipe.h

 // Copyright 2013 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef MOJO_EDK_SYSTEM_DATA_PIPE_H_
 #define MOJO_EDK_SYSTEM_DATA_PIPE_H_
 
 #include <stdint.h>
 
 #include <memory>
@@ skipping 103 matching lines @@
                                     UserPointer<uint32_t> buffer_num_bytes);
   MojoResult ProducerEndWriteData(uint32_t num_bytes_written);
   HandleSignalsState ProducerGetHandleSignalsState();
   MojoResult ProducerAddAwakable(Awakable* awakable,
                                  MojoHandleSignals signals,
                                  bool force,
                                  uint64_t context,
                                  HandleSignalsState* signals_state);
   void ProducerRemoveAwakable(Awakable* awakable,
                               HandleSignalsState* signals_state);
+  void ProducerRemoveAwakableWithContext(Awakable* awakable,
+                                         uint64_t context,
+                                         HandleSignalsState* signals_state);
   void ProducerStartSerialize(Channel* channel,
                               size_t* max_size,
                               size_t* max_platform_handles);
   bool ProducerEndSerialize(
       Channel* channel,
       void* destination,
       size_t* actual_size,
       std::vector<platform::ScopedPlatformHandle>* platform_handles);
 
   // These are called by the consumer dispatcher to implement its methods of
@@ skipping 15 matching lines @@
                                    UserPointer<uint32_t> buffer_num_bytes);
   MojoResult ConsumerEndReadData(uint32_t num_bytes_read);
   HandleSignalsState ConsumerGetHandleSignalsState();
   MojoResult ConsumerAddAwakable(Awakable* awakable,
                                  MojoHandleSignals signals,
                                  bool force,
                                  uint64_t context,
                                  HandleSignalsState* signals_state);
   void ConsumerRemoveAwakable(Awakable* awakable,
                               HandleSignalsState* signals_state);
+  void ConsumerRemoveAwakableWithContext(Awakable* awakable,
+                                         uint64_t context,
+                                         HandleSignalsState* signals_state);
   void ConsumerStartSerialize(Channel* channel,
                               size_t* max_size,
                               size_t* max_platform_handles);
   bool ConsumerEndSerialize(
       Channel* channel,
       void* destination,
       size_t* actual_size,
       std::vector<platform::ScopedPlatformHandle>* platform_handles);
 
   // The following are only to be used by |DataPipeImpl| (and its subclasses):
@@ skipping 138 matching lines @@
   uint32_t consumer_two_phase_max_num_bytes_read_ MOJO_GUARDED_BY(mutex_);
   std::unique_ptr<DataPipeImpl> impl_ MOJO_GUARDED_BY(mutex_);
 
   MOJO_DISALLOW_COPY_AND_ASSIGN(DataPipe);
 };
 
 }  // namespace system
 }  // namespace mojo
 
 #endif  // MOJO_EDK_SYSTEM_DATA_PIPE_H_