Use folly::Function in folly::EventBase

Summary:[Folly] Use `folly::Function` in `folly::EventBase`.

`folly::Function` is moveable but noncopyable and therefore supports wrapping moveable but noncopyable lambdas - like the kind that arises when move-capturing a `std::unique_ptr`.

`std::function` is copyable - therefore it does not support wrapping such noncopyable lambdas.

Switching `folly::EventBase` to use it will allow callers to pass such noncopyable lambdas, allowing, e.g.:

```
auto numptr = folly::make_unique<int>(7); // unique_ptr is noncopyable
folly::EventBase eb;
eb.runInLoop([numptr = std::move(numptr)] { // therefore lambda is noncopyable
  int num = *numptr;
});
eb.loop();
```

This allows us to move away from the `folly::MoveWrapper` hack, which worked like:

```
auto numptr = folly::make_unique<int>(7); // unique_ptr is noncopyable
auto numptrw = folly::makeMoveWrapper(std::move(numptr)); // MoveWrapper is "copyable" - hacky
folly::EventBase eb;
eb.runInLoop([numptrw] { // therefore lambda is "copyable" - hacky
  int num = **numptrw;
});
```

We needed to do that hack while:

But neither condition is true anymore.

Reviewed By: spacedentist

Differential Revision: D3143931

fb-gh-sync-id: 4fbdf5fb77eb5848ed1c6de942b022382141577f
fbshipit-source-id: 4fbdf5fb77eb5848ed1c6de942b022382141577f

wangle/bootstrap/AcceptRoutingHandler.h

@@ -9,6 +9,7 @@
  */
 #pragma once
 
+#include <folly/MoveWrapper.h>
 #include <wangle/bootstrap/RoutingDataHandler.h>
 #include <wangle/bootstrap/ServerBootstrap.h>
 #include <wangle/channel/Pipeline.h>

wangle/channel/OutputBufferingHandler.h

@@ -10,12 +10,13 @@
 
 #pragma once
 
+#include <folly/MoveWrapper.h>
 #include <folly/futures/SharedPromise.h>
-#include <wangle/channel/Handler.h>
-#include <folly/io/async/EventBase.h>
-#include <folly/io/async/EventBaseManager.h>
 #include <folly/io/IOBuf.h>
 #include <folly/io/IOBufQueue.h>
+#include <folly/io/async/EventBase.h>
+#include <folly/io/async/EventBaseManager.h>
+#include <wangle/channel/Handler.h>
 
 namespace wangle {
 

wangle/channel/test/MockHandler.h

@@ -10,6 +10,7 @@
 
 #pragma once
 
+#include <folly/MoveWrapper.h>
 #include <gmock/gmock.h>
 #include <wangle/channel/Handler.h>
 

wangle/concurrent/FutureExecutor.h

@@ -9,6 +9,7 @@
  */
 
 #pragma once
+#include <folly/MoveWrapper.h>
 #include <folly/futures/Future.h>
 
 namespace wangle {

wangle/concurrent/PriorityThreadFactory.h

@@ -15,6 +15,8 @@
 #include <sys/time.h>
 #include <sys/resource.h>
 
+#include <folly/MoveWrapper.h>
+
 namespace wangle {
 
 /**

wangle/service/ExecutorFilter.h

@@ -1,5 +1,16 @@
+/*
+ * Copyright (c) 2016, Facebook, Inc.
+ * All rights reserved.
+ *
+ * This source code is licensed under the BSD-style license found in the
+ * LICENSE file in the root directory of this source tree. An additional grant
+ * of patent rights can be found in the PATENTS file in the same directory.
+ *
+ */
+
 #pragma once
 
+#include <folly/MoveWrapper.h>
 #include <wangle/service/Service.h>
 
 namespace wangle {