[NTP Snippets] Schedule periodic fetching

chrome/browser/android/ntp_snippets_launcher.cc

+// Copyright 2016 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 "chrome/browser/android/ntp_snippets_launcher.h"
+
+#include "base/android/context_utils.h"
+#include "content/public/browser/browser_thread.h"
+#include "jni/SnippetsLauncher_jni.h"
+
+using content::BrowserThread;
+
+namespace {
+
+base::LazyInstance<NTPSnippetsLauncher> g_snippets_launcher =
+    LAZY_INSTANCE_INITIALIZER;
+
+}  // namespace
+
+// static
+NTPSnippetsLauncher* NTPSnippetsLauncher::Get() {
+  DCHECK_CURRENTLY_ON(BrowserThread::UI);
+  return g_snippets_launcher.Pointer();
+}
+
+// static
+bool NTPSnippetsLauncher::Register(JNIEnv* env) {
+  return RegisterNativesImpl(env);
+}
+
+bool NTPSnippetsLauncher::Schedule(int period_seconds) {
+  DCHECK_CURRENTLY_ON(BrowserThread::UI);
+
+  JNIEnv* env = base::android::AttachCurrentThread();
+  return Java_SnippetsLauncher_schedule(
+      env, java_launcher_.obj(), period_seconds);
+}
+
+bool NTPSnippetsLauncher::Unschedule() {
+  DCHECK_CURRENTLY_ON(BrowserThread::UI);
+
+  JNIEnv* env = base::android::AttachCurrentThread();
+  return Java_SnippetsLauncher_unschedule(env, java_launcher_.obj());
+}
+
+NTPSnippetsLauncher::NTPSnippetsLauncher() {
+  DCHECK_CURRENTLY_ON(BrowserThread::UI);
+
+  JNIEnv* env = base::android::AttachCurrentThread();
+  java_launcher_.Reset(Java_SnippetsLauncher_create(
+      env, base::android::GetApplicationContext()));
+}
+
+NTPSnippetsLauncher::~NTPSnippetsLauncher() {
+  DCHECK_CURRENTLY_ON(BrowserThread::UI);
+
+  JNIEnv* env = base::android::AttachCurrentThread();
+  Java_SnippetsLauncher_destroy(env, java_launcher_.obj());
+  java_launcher_.Reset();
+}