[BackgroundSync] Trigger Background Sync events when Chrome is backgrounded on Android

content/browser/android/background_sync_network_observer_android.cc

+// Copyright 2015 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 "content/browser/android/background_sync_network_observer_android.h"
+
+#include "jni/BackgroundSyncNetworkObserver_jni.h"
+
+namespace content {
+
+// static
+bool BackgroundSyncNetworkObserverAndroid::Observer::RegisterNetworkObserver(
+    JNIEnv* env) {
+  return RegisterNativesImpl(env);
+}
+
+// static
+scoped_refptr<BackgroundSyncNetworkObserverAndroid::Observer>
+BackgroundSyncNetworkObserverAndroid::Observer::Create(
+    base::Callback<void(net::NetworkChangeNotifier::ConnectionType)> callback) {
+  DCHECK_CURRENTLY_ON(BrowserThread::IO);
+  scoped_refptr<BackgroundSyncNetworkObserverAndroid::Observer> observer(
+      new BackgroundSyncNetworkObserverAndroid::Observer(callback));
+  BrowserThread::PostTask(
+      BrowserThread::UI, FROM_HERE,
+      base::Bind(&BackgroundSyncNetworkObserverAndroid::Observer::Init,
+                 observer));
+  return observer;
+}
+
+void BackgroundSyncNetworkObserverAndroid::Observer::Init() {
+  DCHECK_CURRENTLY_ON(BrowserThread::UI);
+  // Attach a Java BackgroundSyncNetworkObserver object. Its lifetime will be
+  // scoped to the lifetime of this object.
+  env_ = base::android::AttachCurrentThread();
+  base::android::ScopedJavaGlobalRef<jobject> obj(
+      Java_BackgroundSyncNetworkObserver_createObserver(
+          env_, base::android::GetApplicationContext(),
+          reinterpret_cast<jlong>(this)));
+  j_observer_.Reset(obj);
+}
+
+BackgroundSyncNetworkObserverAndroid::Observer::~Observer() {
+  Java_BackgroundSyncNetworkObserver_removeObserver(
+      env_, j_observer_.obj(), reinterpret_cast<jlong>(this));

[jkarlin, 2015/09/19 00:16:06]

DCHECK_CURRENTLY_ON(BrowserThread::UI);

[iclelland, 2015/09/21 18:49:30]

I figured that DeleteOnUIThread<> made that redundant, but done.

+  j_observer_.Release();
+}
+
+void BackgroundSyncNetworkObserverAndroid::Observer::
+    NotifyConnectionTypeChanged(JNIEnv* env,
+                                jobject jcaller,
+                                jint new_connection_type) {
+  DCHECK_CURRENTLY_ON(BrowserThread::UI);
+  BrowserThread::PostTask(
+      BrowserThread::IO, FROM_HERE,
+      base::Bind(callback_,
+                 static_cast<net::NetworkChangeNotifier::ConnectionType>(
+                     new_connection_type)));
+}
+
+BackgroundSyncNetworkObserverAndroid::Observer::Observer(
+    base::Callback<void(net::NetworkChangeNotifier::ConnectionType)> callback)
+    : callback_(callback) {}

[jkarlin, 2015/09/19 00:16:06]

DCHECK_CURRENTLY_ON(BrowserThread::IO);

[iclelland, 2015/09/21 18:49:30]

Done.

+
+BackgroundSyncNetworkObserverAndroid::BackgroundSyncNetworkObserverAndroid(
+    const base::Closure& network_changed_callback)
+    : BackgroundSyncNetworkObserver(network_changed_callback),
+      weak_ptr_factory_(this) {
+  DCHECK_CURRENTLY_ON(BrowserThread::IO);
+
+  // Remove the observer attached by the NetworkObserver constructor
+  net::NetworkChangeNotifier::RemoveNetworkChangeObserver(this);
+
+  observer_ = Observer::Create(
+      base::Bind(&BackgroundSyncNetworkObserverAndroid::OnNetworkChanged,
+                 weak_ptr_factory_.GetWeakPtr()));
+}
+
+// static
+void BackgroundSyncNetworkObserverAndroid::DisableNotificationForTesting() {

[jkarlin, 2015/09/19 00:16:06]

Looks like you call this on UI. Please rename to
DisableNotificationForTestingOnUIThread and add a dcheck.

[iclelland, 2015/09/21 18:49:30]

Renamed. It's too early to check here, though -- I think that SetUp is called
before any thread message loops exist, so I can't actually DCHECK_CURRENTLY_ON
anything.

I added a check on the Java side to ensure that it is actually on the UI thread
there.

+  JNIEnv* env = base::android::AttachCurrentThread();
+  Java_BackgroundSyncNetworkObserver_disableNotificationForTesting(env);
+}
+
+BackgroundSyncNetworkObserverAndroid::~BackgroundSyncNetworkObserverAndroid() {
+  DCHECK_CURRENTLY_ON(BrowserThread::IO);
+}
+}  // namespace content