Implement a Mojo service for Background Fetch

third_party/WebKit/Source/modules/background_fetch/BackgroundFetchedEvent.cpp

 // 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 "modules/background_fetch/BackgroundFetchedEvent.h"
 
+#include "bindings/core/v8/ScriptPromiseResolver.h"
 #include "bindings/core/v8/ScriptState.h"
 #include "core/dom/DOMException.h"
 #include "modules/EventModulesNames.h"
+#include "modules/background_fetch/BackgroundFetchBridge.h"
 #include "modules/background_fetch/BackgroundFetchSettledRequest.h"
 #include "modules/background_fetch/BackgroundFetchedEventInit.h"
 
 namespace blink {
 
 BackgroundFetchedEvent::BackgroundFetchedEvent(
     const AtomicString& type,
-    const BackgroundFetchedEventInit& init)
+    const BackgroundFetchedEventInit& init,
+    ServiceWorkerRegistration* registration)
     : BackgroundFetchEvent(type, init),
-      m_completedFetches(init.completedFetches()) {}
+      m_completedFetches(init.completedFetches()),
+      m_registration(registration) {}
 
 BackgroundFetchedEvent::~BackgroundFetchedEvent() = default;
 
 HeapVector<Member<BackgroundFetchSettledRequest>>
 BackgroundFetchedEvent::completedFetches() const {
   return m_completedFetches;
 }
 
 ScriptPromise BackgroundFetchedEvent::updateUI(ScriptState* scriptState,
-                                               String title) {
-  return ScriptPromise::rejectWithDOMException(
-      scriptState,
-      DOMException::create(NotSupportedError, "Not implemented yet."));
+                                               const String& title) {
+  if (!m_registration) {
+    // Return a Promise that will never settle when a developer calls this
+    // method on a BackgroundFetchedEvent instance they created themselves.
+    return ScriptPromise();
+  }
+
+  ScriptPromiseResolver* resolver = ScriptPromiseResolver::create(scriptState);
+  ScriptPromise promise = resolver->promise();
+
+  BackgroundFetchBridge::from(m_registration)
+      ->updateUI(tag(), title,
+                 WTF::bind(&BackgroundFetchedEvent::didUpdateUI,
+                           wrapPersistent(this), wrapPersistent(resolver)));
+
+  return promise;
+}
+
+void BackgroundFetchedEvent::didUpdateUI(
+    ScriptPromiseResolver* resolver,
+    mojom::blink::BackgroundFetchError error) {
+  switch (error) {
+    case mojom::blink::BackgroundFetchError::NONE:
+      resolver->resolve();

[dcheng, 2017/03/16 07:14:08]

Nit: this still ends up in the NOTREACHED(), should there be a return after
this?

[Peter Beverloo, 2017/03/16 16:26:55]

Done.

+      break;
+    case mojom::blink::BackgroundFetchError::DUPLICATED_TAG:
+      // Not applicable for this callback.
+      break;
+  }
+
+  NOTREACHED();
 }
 
 const AtomicString& BackgroundFetchedEvent::interfaceName() const {
   return EventNames::BackgroundFetchedEvent;
 }
 
 DEFINE_TRACE(BackgroundFetchedEvent) {
   visitor->trace(m_completedFetches);
+  visitor->trace(m_registration);
   BackgroundFetchEvent::trace(visitor);
 }
 
 }  // namespace blink