Add HeadlessTabSocket

headless/lib/browser/headless_tab_socket_impl.cc

Index: headless/lib/browser/headless_tab_socket_impl.cc
diff --git a/headless/lib/browser/headless_tab_socket_impl.cc b/headless/lib/browser/headless_tab_socket_impl.cc
new file mode 100644
index 0000000000000000000000000000000000000000..a488ca0e2dbaefa8863e4ff8334328197790333b
--- /dev/null
+++ b/headless/lib/browser/headless_tab_socket_impl.cc
@@ -0,0 +1,85 @@
+// 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) {
+  AwaitNextMessageFromEmbedderCallback callback;
+
+  {
+    base::AutoLock lock(lock_);
+    if (waiting_for_message_cb_.is_null() || !outgoing_message_queue_.empty()) {
+      outgoing_message_queue_.push_back(message);
+      return;
+    } else {
+      callback = waiting_for_message_cb_;
+      waiting_for_message_cb_ = AwaitNextMessageFromEmbedderCallback();
+      DCHECK(waiting_for_message_cb_.is_null());
+    }
+  }
+
+  callback.Run(message);
+}
+
+void HeadlessTabSocketImpl::SetListener(Listener* listener) {
+  std::list<std::string> messages;
+
+  {
+    base::AutoLock lock(lock_);
+    listener_ = listener;
+    if (!listener)
+      return;
+
+    std::swap(messages, incoming_message_queue_);
+  }
+
+  for (const std::string& message : messages) {
+    listener_->OnMessageFromTab(message);
+  }
+}
+
+void HeadlessTabSocketImpl::SendMessageToEmbedder(const std::string& message) {
+  Listener* listener = nullptr;
+  {
+    base::AutoLock lock(lock_);
+    if (listener_) {
+      listener = listener_;
+    } else {
+      incoming_message_queue_.push_back(message);
+      return;
+    }
+  }
+
+  listener->OnMessageFromTab(message);
+}
+
+void HeadlessTabSocketImpl::AwaitNextMessageFromEmbedder(
+    const AwaitNextMessageFromEmbedderCallback& callback) {
+  std::string message;
+  {
+    base::AutoLock lock(lock_);
+    if (outgoing_message_queue_.empty()) {
+      waiting_for_message_cb_ = callback;
+      DCHECK(!waiting_for_message_cb_.is_null());
+      return;
+    } else {
+      message = outgoing_message_queue_.front();
+      outgoing_message_queue_.pop_front();
+    }
+  }
+  callback.Run(message);
+}
+
+void HeadlessTabSocketImpl::CreateMojoService(
+    mojo::InterfaceRequest<TabSocket> request) {
+  mojo_bindings_.AddBinding(this, std::move(request));
+}
+
+}  // namespace headless