Connect BackgroundFetch to the OfflineItemCollection

chrome/browser/background_fetch/background_fetch_client_impl.cc

Index: chrome/browser/background_fetch/background_fetch_client_impl.cc
diff --git a/chrome/browser/background_fetch/background_fetch_client_impl.cc b/chrome/browser/background_fetch/background_fetch_client_impl.cc
new file mode 100644
index 0000000000000000000000000000000000000000..48d1655b0895cad1ea3b0801858b99fe63f3746d
--- /dev/null
+++ b/chrome/browser/background_fetch/background_fetch_client_impl.cc
@@ -0,0 +1,115 @@
+// 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 <string>
+
+#include "chrome/browser/background_fetch/background_fetch_client_impl.h"
+
+#include "chrome/browser/offline_items_collection/offline_content_aggregator_factory.h"
+#include "chrome/browser/profiles/profile.h"
+#include "components/offline_items_collection/core/offline_content_aggregator.h"
+#include "components/offline_items_collection/core/offline_item.h"
+
+namespace {
+
+const char kBackgroundFetchNamespace[] = "BackgroundFetchNamespace";
+
+}  // namespace
+
+BackgroundFetchClientImpl::BackgroundFetchClientImpl(Profile* profile)
+    : profile_(profile) {
+  DCHECK(profile_);
+  offline_items_collection::OfflineContentAggregator* aggregator =

[Peter Beverloo, 2017/03/31 01:32:22]

Could we have an GetAggregator() helper method that does these three lines?

[Peter Beverloo, 2017/03/31 01:32:22]

`using` declarations are allowed in .cc files, so that'll help a bit

[harkness, 2017/03/31 10:11:43]

It would only be called twice. I thought Chromium had rule of 3?

[harkness, 2017/03/31 10:11:43]

Done.

[Peter Beverloo, 2017/03/31 11:54:06]

Fair enough.

+      offline_items_collection::OfflineContentAggregatorFactory::
+          GetForBrowserContext(profile_);
+  if (!aggregator)
+    return;
+  aggregator->RegisterProvider(kBackgroundFetchNamespace, this);
+}
+
+BackgroundFetchClientImpl::~BackgroundFetchClientImpl() = default;
+
+void BackgroundFetchClientImpl::Shutdown() {
+  offline_items_collection::OfflineContentAggregator* aggregator =
+      offline_items_collection::OfflineContentAggregatorFactory::
+          GetForBrowserContext(profile_);
+  if (!aggregator)
+    return;
+  aggregator->UnregisterProvider(kBackgroundFetchNamespace);
+}
+
+void BackgroundFetchClientImpl::SetDelegate(
+    content::BackgroundFetchClient::Delegate* delegate) {
+  delegate_ = delegate;
+}
+
+void BackgroundFetchClientImpl::CancelDownload(
+    const offline_items_collection::ContentId& content_id) {
+  DCHECK_EQ(content_id.name_space, kBackgroundFetchNamespace);
+
+  if (!delegate_)
+    return;
+
+  delegate_->CancelDownload(content_id.id);
+}
+
+void BackgroundFetchClientImpl::PauseDownload(
+    const offline_items_collection::ContentId& content_id) {
+  DCHECK_EQ(content_id.name_space, kBackgroundFetchNamespace);
+
+  if (!delegate_)
+    return;
+
+  delegate_->PauseDownload(content_id.id);
+}
+
+void BackgroundFetchClientImpl::ResumeDownload(
+    const offline_items_collection::ContentId& content_id) {
+  DCHECK_EQ(content_id.name_space, kBackgroundFetchNamespace);
+
+  if (!delegate_)
+    return;
+
+  delegate_->ResumeDownload(content_id.id);
+}
+
+void BackgroundFetchClientImpl::OpenItem(
+    const offline_items_collection::ContentId& content_id) {
+  // TODO(harkness): Add another call to BackgroundFetchClient::Delegate and
+  // plumb this to 'onclickevent' to the ServiceWorker.
+}
+
+void BackgroundFetchClientImpl::AddObserver(Observer* observer) {
+  // TODO(harkness): Add a path for the OfflineContentProvider to observe
+  // changes in available BackgroundFetch items.
+}
+
+void BackgroundFetchClientImpl::RemoveObserver(Observer* observer) {}
+
+bool BackgroundFetchClientImpl::AreItemsAvailable() {
+  // This call has no meaning for BackgroundFetch, since items will be removed
+  // from the offline content listing as soon as the fetch is complete.

[Peter Beverloo, 2017/03/31 01:32:22]

Yes, but the OIC may maintain a cache of its own. Dito for the other methods,
I'd be more comfortable if we were to ask David.

[harkness, 2017/03/31 10:11:43]

Updated to be a TODO.

+  return false;
+}
+
+void BackgroundFetchClientImpl::RemoveItem(
+    const offline_items_collection::ContentId& content_id) {
+  // This call has no meaning for BackgroundFetch, since items will be removed
+  // from the offline content listing as soon as the fetch is complete.
+}
+
+const offline_items_collection::OfflineItem*
+BackgroundFetchClientImpl::GetItemById(
+    const offline_items_collection::ContentId& content_id) {
+  // This call has no meaning for BackgroundFetch, since items will be removed
+  // from the offline content listing as soon as the fetch is complete.
+  return nullptr;
+}
+
+offline_items_collection::OfflineContentProvider::OfflineItemList
+BackgroundFetchClientImpl::GetAllItems() {
+  // This call has no meaning for BackgroundFetch, since items will be removed
+  // from the offline content listing as soon as the fetch is complete.
+  return offline_items_collection::OfflineContentProvider::OfflineItemList();
+}