Reland "EDK: Move //mojo/edk/system/waitable_event* to edk/util."

mojo/edk/system/test_channel_endpoint_client.h

 // Copyright 2015 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_TEST_CHANNEL_ENDPOINT_CLIENT_H_
 #define MOJO_EDK_SYSTEM_TEST_CHANNEL_ENDPOINT_CLIENT_H_
 
 #include <memory>
 
 #include "mojo/edk/system/channel_endpoint.h"
 #include "mojo/edk/system/channel_endpoint_client.h"
 #include "mojo/edk/system/message_in_transit_queue.h"
 #include "mojo/edk/util/mutex.h"
 #include "mojo/edk/util/ref_ptr.h"
 #include "mojo/edk/util/thread_annotations.h"
 #include "mojo/public/cpp/system/macros.h"
 
 namespace mojo {
+
+namespace util {
+class ManualResetWaitableEvent;
+}
+
 namespace system {
-
-class ManualResetWaitableEvent;
-
 namespace test {
 
 class TestChannelEndpointClient final : public ChannelEndpointClient {
  public:
   // Note: Use |util::MakeRefCounted<TestChannelEndpointClient>()|.
 
   // Initializes with the given port and endpoint.
   void Init(unsigned port, util::RefPtr<ChannelEndpoint>&& endpoint);
 
   // Returns true if we're detached from the |ChannelEndpoint|.
   bool IsDetached() const;
 
   // Gets the current number of messages received (but not dequeued).
   size_t NumMessages() const;
 
   // Gets/removes a message that was received (|NumMessages()| must be
   // non-zero), in FIFO order.
   std::unique_ptr<MessageInTransit> PopMessage();
 
   // Sets an event to signal when we receive a message. (|read_event| must live
   // until this object is destroyed or the read event is reset to null.)
-  void SetReadEvent(ManualResetWaitableEvent* read_event);
+  void SetReadEvent(util::ManualResetWaitableEvent* read_event);
 
   // |ChannelEndpointClient| implementation:
   bool OnReadMessage(unsigned port, MessageInTransit* message) override;
   void OnDetachFromChannel(unsigned port) override;
 
  private:
   FRIEND_MAKE_REF_COUNTED(TestChannelEndpointClient);
 
   TestChannelEndpointClient();
   ~TestChannelEndpointClient() override;
 
   mutable util::Mutex mutex_;
 
   unsigned port_ MOJO_GUARDED_BY(mutex_);
   util::RefPtr<ChannelEndpoint> endpoint_ MOJO_GUARDED_BY(mutex_);
 
   MessageInTransitQueue messages_ MOJO_GUARDED_BY(mutex_);
 
   // Event to trigger if we read a message (may be null).
-  ManualResetWaitableEvent* read_event_ MOJO_GUARDED_BY(mutex_);
+  util::ManualResetWaitableEvent* read_event_ MOJO_GUARDED_BY(mutex_);
 
   MOJO_DISALLOW_COPY_AND_ASSIGN(TestChannelEndpointClient);
 };
 
 }  // namespace test
 }  // namespace system
 }  // namespace mojo
 
 #endif  // MOJO_EDK_SYSTEM_TEST_CHANNEL_ENDPOINT_CLIENT_H_