[AndroidSmsService] Dispatch message to establish connection in service worker

This adds a StartServiceWorkerAndDispatchLongRunningMessage call in
ConnectionEstablisherImpl to initiate background connection between
Android Messages for Web service worker to and the Tachyon backend.

Bug: 850823
Change-Id: I71b448b46f5802f741a1d7b6b4f09367defb0365
Reviewed-on: https://chromium-review.googlesource.com/1180417Reviewed-by: Kyle Horimoto <khorimoto@chromium.org>
Reviewed-by: Jeremy Klein <jlklein@chromium.org>
Commit-Queue: Azeem Arshad <azeemarshad@chromium.org>
Cr-Commit-Position: refs/heads/master@{#584235}

chrome/browser/chromeos/android_sms/connection_establisher_impl.cc

@@ -3,21 +3,53 @@
 // found in the LICENSE file.
 
 #include "chrome/browser/chromeos/android_sms/connection_establisher_impl.h"
+#include "base/strings/utf_string_conversions.h"
+#include "chrome/browser/chromeos/android_sms/android_sms_urls.h"
+#include "content/public/browser/browser_thread.h"
+#include "third_party/blink/public/common/message_port/string_message_codec.h"
 
 namespace chromeos {
 
 namespace android_sms {
 
+namespace {
+const char kStartStreamingMessageString[] = "start_streaming_connection";
+}
+
 ConnectionEstablisherImpl::ConnectionEstablisherImpl() = default;
 ConnectionEstablisherImpl::~ConnectionEstablisherImpl() = default;
 
 void ConnectionEstablisherImpl::EstablishConnection(
     content::ServiceWorkerContext* service_worker_context) {
-  // TODO(azeemarshad): Send connection message to service worker using
-  // ServiceWorkerContext::StartServiceWorkerAndDispatchLongRunningMessage
-  // when https://chromium-review.googlesource.com/c/chromium/src/+/1119580
-  // is ready.
-  return;
+  content::BrowserThread::PostTask(
+      content::BrowserThread::IO, FROM_HERE,
+      base::BindOnce(&ConnectionEstablisherImpl::SendStartStreamingMessage,
+                     base::Unretained(this), service_worker_context));
+}
+
+void ConnectionEstablisherImpl::SendStartStreamingMessage(
+    content::ServiceWorkerContext* service_worker_context) {
+  DCHECK_CURRENTLY_ON(content::BrowserThread::IO);
+  if (is_connected_)
+    return;
+
+  blink::TransferableMessage msg;
+  msg.owned_encoded_message = blink::EncodeStringMessage(
+      base::UTF8ToUTF16(kStartStreamingMessageString));
+  msg.encoded_message = msg.owned_encoded_message;
+
+  is_connected_ = true;
+  service_worker_context->StartServiceWorkerAndDispatchLongRunningMessage(
+      GetAndroidMessagesURL(), std::move(msg),
+      base::BindOnce(&ConnectionEstablisherImpl::OnMessageDispatchResult,
+                     base::Unretained(this)));
+}
+
+void ConnectionEstablisherImpl::OnMessageDispatchResult(bool status) {
+  // When message dispatch result callback is called, it means that the service
+  // worker resolved it's message handler promise and is not holding a
+  // background connection.
+  is_connected_ = false;
 }
 
 }  // namespace android_sms

chrome/browser/chromeos/android_sms/connection_establisher_impl.h

@@ -26,6 +26,11 @@ class ConnectionEstablisherImpl : public ConnectionEstablisher {
       content::ServiceWorkerContext* service_worker_context) override;
 
  private:
+  void SendStartStreamingMessage(
+      content::ServiceWorkerContext* service_worker_context);
+  void OnMessageDispatchResult(bool status);
+
+  bool is_connected_ = false;
   DISALLOW_COPY_AND_ASSIGN(ConnectionEstablisherImpl);
 };