Add HeadlessTabSocket

headless/lib/browser/headless_tab_socket_impl.cc

+// Copyright 2017 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.
+
+#include "headless/lib/browser/headless_tab_socket_impl.h"
+
+namespace headless {
+
+HeadlessTabSocketImpl::HeadlessTabSocketImpl() : listener_(nullptr) {}
+
+HeadlessTabSocketImpl::~HeadlessTabSocketImpl() {}
+
+void HeadlessTabSocketImpl::SendMessageToTab(const std::string& message) {
+  base::AutoLock lock(lock_);
+  if (waiting_for_message_cb_.is_null() || !out_going_message_queue_.empty()) {
+    out_going_message_queue_.push_back(message);
+  } else {
+    waiting_for_message_cb_.Run(message);

[Sami, 2017/04/12 14:18:45]

Ditto about locking.

[alex clarke (OOO till 29th), 2017/04/12 15:47:46]

Done.

+    waiting_for_message_cb_ = AwaitNextMessageFromEmbedderCallback();
+    DCHECK(waiting_for_message_cb_.is_null());
+  }
+}
+
+void HeadlessTabSocketImpl::SetListener(Listener* listener) {
+  base::AutoLock lock(lock_);
+  listener_ = listener;
+  if (!listener)
+    return;
+
+  for (const std::string& message : incomming_message_queue_) {
+    listener_->OnMessageFromTab(message);

[Sami, 2017/04/12 14:18:45]

Could we do this outside the lock? Otherwise you can't always reply to a message
from the callback.

[alex clarke (OOO till 29th), 2017/04/12 15:47:46]

Done.

[Sami, 2017/04/12 16:09:06]

Looks like we're still holding the lock here?

[alex clarke (OOO till 29th), 2017/04/12 19:41:48]

Oops done.

+  }
+  incomming_message_queue_.clear();
+}
+
+void HeadlessTabSocketImpl::SendMessageToEmbedder(const std::string& message) {
+  base::AutoLock lock(lock_);
+  if (listener_) {
+    listener_->OnMessageFromTab(message);
+  } else {
+    incomming_message_queue_.push_back(message);
+  }
+}
+
+void HeadlessTabSocketImpl::AwaitNextMessageFromEmbedder(
+    const AwaitNextMessageFromEmbedderCallback& callback) {
+  base::AutoLock lock(lock_);
+  if (out_going_message_queue_.empty()) {
+    waiting_for_message_cb_ = callback;
+    DCHECK(!waiting_for_message_cb_.is_null());
+  } else {
+    callback.Run(out_going_message_queue_.front());

[Sami, 2017/04/12 14:18:45]

Ditto about locking.

[alex clarke (OOO till 29th), 2017/04/12 15:47:46]

Done.

+    out_going_message_queue_.pop_front();
+  }
+}
+
+void HeadlessTabSocketImpl::CreateMojoService(
+    mojo::InterfaceRequest<TabSocket> request) {
+  mojo_bindings_.AddBinding(this, std::move(request));
+}
+
+}  // namespace headless