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diff --git a/include/perfetto/ipc/deferred.h b/include/perfetto/ipc/deferred.h
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+/*
+ * Copyright (C) 2017 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#ifndef INCLUDE_PERFETTO_IPC_DEFERRED_H_
+#define INCLUDE_PERFETTO_IPC_DEFERRED_H_
+
+#include <functional>
+#include <memory>
+#include <utility>
+
+#include "perfetto/ipc/async_result.h"
+#include "perfetto/ipc/basic_types.h"
+
+namespace perfetto {
+namespace ipc {
+
+// This class is a wrapper for a callback handling async results.
+// The problem this is solving is the following: For each result argument of the
+// methods generated from the .proto file:
+// - The client wants to see something on which it can Bind() a callback, which
+//   is invoked asynchronously once reply is received from the host.
+// - The host wants to expose something to user code that implements the IPC
+//   methods to allow them to provide an asynchronous reply back to the client.
+//   Eventually even more than once, for the case streaming replies.
+//
+// In both cases we want to make sure that callbacks don't get lost along the
+// way. To address this, this class will automatically reject the callbacks
+// if they are not resolved at destructor time (or the object is std::move()'d).
+//
+// The client is supposed to use this class as follows:
+//   class GreeterProxy {
+//      void SayHello(const HelloRequest&, Deferred<HelloReply> reply)
+//   }
+//  ...
+//  Deferred<HelloReply> reply;
+//  reply.Bind([] (AsyncResult<HelloReply> reply) {
+//    std::cout << reply.success() ? reply->message : "failure";
+//  });
+//  host_proxy_instance.SayHello(req, std::move(reply));
+//
+// The host instead is supposed to use this as follows:
+//   class GreeterImpl : public Greeter {
+//     void SayHello(const HelloRequest& req, Deferred<HelloReply> reply) {
+//        AsyncResult<HelloReply> reply = AsyncResult<HelloReply>::Create();
+//        reply->set_greeting("Hello " + req.name)
+//        reply.Resolve(std::move(reply));
+//     }
+//   }
+// Or for more complex cases, the deferred object can be std::move()'d outside
+// and the reply can continue asynchronously later.
+
+template <typename T>
+class Deferred;
+
+class DeferredBase {
+ public:
+  explicit DeferredBase(
+      std::function<void(AsyncResult<ProtoMessage>)> callback = nullptr);
+
+  template <typename T>
+  explicit DeferredBase(Deferred<T> other)
+      : callback_(std::move(other.callback_)) {}
+
+  ~DeferredBase();
+  DeferredBase(DeferredBase&&) noexcept;
+  DeferredBase& operator=(DeferredBase&&);
+  void Bind(std::function<void(AsyncResult<ProtoMessage>)> callback);
+  bool IsBound() const;
+  void Resolve(AsyncResult<ProtoMessage>);
+  void Reject();
+
+ protected:
+  template <typename T>
+  friend class Deferred;
+  void Move(DeferredBase&);
+
+  std::function<void(AsyncResult<ProtoMessage>)> callback_;
+};
+
+template <typename T = ProtoMessage>
+class Deferred : public DeferredBase {
+ public:
+  explicit Deferred(std::function<void(AsyncResult<T>)> callback = nullptr) {
+    Bind(std::move(callback));
+  }
+
+  // This move constructor (and the similar one in DeferredBase) is meant to be
+  // called only by the autogenerated code. The caller has to guarantee that the
+  // moved-from and moved-to types match. The behavior is otherwise undefined.
+  explicit Deferred(DeferredBase&& other) {
+    callback_ = std::move(other.callback_);
+    other.callback_ = nullptr;
+  }
+
+  void Bind(std::function<void(AsyncResult<T>)> callback) {
+    if (!callback)
+      return;
+
+    // Here we need a callback adapter to downcast the callback to a generic
+    // callback that takes an AsyncResult<ProtoMessage>, so that it can be
+    // stored in the base class |callback_|.
+    auto callback_adapter = [callback](
+                                AsyncResult<ProtoMessage> async_result_base) {
+      // Upcast the async_result from <ProtoMessage> -> <T : ProtoMessage>.
+      static_assert(std::is_base_of<ProtoMessage, T>::value, "T:ProtoMessage");
+      AsyncResult<T> async_result(
+          std::unique_ptr<T>(static_cast<T*>(async_result_base.release_msg())),
+          async_result_base.has_more(), async_result_base.fd());
+      callback(std::move(async_result));
+    };
+    DeferredBase::Bind(callback_adapter);
+  }
+
+  // If no more messages are expected, |callback_| is released.
+  void Resolve(AsyncResult<T> async_result) {
+    // Convert the |async_result| to the generic base one (T -> ProtoMessage).
+    AsyncResult<ProtoMessage> async_result_base(
+        std::unique_ptr<ProtoMessage>(async_result.release_msg()),
+        async_result.has_more(), async_result.fd());
+    DeferredBase::Resolve(std::move(async_result_base));
+  }
+};
+
+}  // namespace ipc
+}  // namespace perfetto
+
+#endif  // INCLUDE_PERFETTO_IPC_DEFERRED_H_