[mojo-edk] Add MojoWatch and MojoCancelWatch APIs

mojo/edk/system/platform_handle_dispatcher.h

 // Copyright 2014 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_PLATFORM_HANDLE_DISPATCHER_H_
 #define MOJO_EDK_SYSTEM_PLATFORM_HANDLE_DISPATCHER_H_
 
 #include "base/macros.h"
 #include "base/memory/ref_counted.h"
 #include "base/synchronization/lock.h"
 #include "mojo/edk/embedder/scoped_platform_handle.h"
 #include "mojo/edk/system/dispatcher.h"
 #include "mojo/edk/system/system_impl_export.h"
 
 namespace mojo {
 namespace edk {
 
 class MOJO_SYSTEM_IMPL_EXPORT PlatformHandleDispatcher : public Dispatcher {
  public:
   static scoped_refptr<PlatformHandleDispatcher> Create(
       ScopedPlatformHandle platform_handle);
 
   ScopedPlatformHandle PassPlatformHandle();
 
   // Dispatcher:
   Type GetType() const override;
-  MojoResult Close() override;
+  MojoResult Close(RequestContext* request_context) override;
   void StartSerialize(uint32_t* num_bytes,
                       uint32_t* num_ports,
                       uint32_t* num_handles) override;
   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<PlatformHandleDispatcher> Deserialize(
       const void* bytes,
       size_t num_bytes,
       const ports::PortName* ports,
       size_t num_ports,
       PlatformHandle* handles,
       size_t num_handles);
 
  private:
   PlatformHandleDispatcher(ScopedPlatformHandle platform_handle);
   ~PlatformHandleDispatcher() override;
 
   base::Lock lock_;
   bool in_transit_ = false;
   bool is_closed_ = false;
   ScopedPlatformHandle platform_handle_;
 
   DISALLOW_COPY_AND_ASSIGN(PlatformHandleDispatcher);
 };
 
 }  // namespace edk
 }  // namespace mojo
 
 #endif  // MOJO_EDK_SYSTEM_PLATFORM_HANDLE_DISPATCHER_H_