diff -r 000000000000 -r 6474c204b198 mobile/android/base/background/announcements/AnnouncementsFetcher.java
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/mobile/android/base/background/announcements/AnnouncementsFetcher.java	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,134 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+package org.mozilla.gecko.background.announcements;
+
+import java.io.UnsupportedEncodingException;
+import java.net.URI;
+import java.net.URISyntaxException;
+import java.net.URLEncoder;
+
+import org.mozilla.gecko.background.common.GlobalConstants;
+import org.mozilla.gecko.background.common.log.Logger;
+import org.mozilla.gecko.sync.net.BaseResource;
+
+public class AnnouncementsFetcher {
+  private static final String LOG_TAG = "AnnounceFetch";
+  private static final long MILLISECONDS_PER_DAY = 24 * 60 * 60 * 1000;
+
+  public static URI getSnippetURI(String base, String channel,
+                                  String version, String platform,
+                                  int idleDays)
+    throws URISyntaxException {
+    try {
+      final String c = URLEncoder.encode(channel, "UTF-8");
+      final String v = URLEncoder.encode(version, "UTF-8");
+      final String p = URLEncoder.encode(platform, "UTF-8");
+      final String s = base + c + "/" + v + "/" + p + ((idleDays == -1) ? "" : ("?idle=" + idleDays));
+      return new URI(s);
+    } catch (UnsupportedEncodingException e) {
+      // Nonsense.
+      return null;
+    }
+  }
+
+  public static URI getAnnounceURI(final String baseURL, final long lastLaunch) throws URISyntaxException {
+    final String channel = getChannel();
+    final String version = getVersion();
+    final String platform = getPlatform();
+    final int idleDays = getIdleDays(lastLaunch);
+
+    Logger.debug(LOG_TAG, "Fetch URI: idle for " + idleDays + " days.");
+    return getSnippetURI(baseURL, channel, version, platform, idleDays);
+  }
+
+  protected static String getChannel() {
+    return AnnouncementsConstants.ANNOUNCE_CHANNEL;
+  }
+
+  protected static String getVersion() {
+    return GlobalConstants.MOZ_APP_VERSION;
+  }
+
+  protected static String getPlatform() {
+    return GlobalConstants.ANDROID_CPU_ARCH;
+  }
+
+  /**
+   * Return the number of days that we've been idle, assuming that we have a
+   * sane last launch time and the current time is within range. If no sane idle
+   * time can be returned, we return -1.
+   *
+   * @param lastLaunch
+   *          Time at which the browser was last launched, in milliseconds since epoch.
+   * @param now
+   *          Milliseconds since epoch for which idle time should be calculated.
+   * @return number of idle days, or -1 if out of range.
+   */
+  protected static int getIdleDays(final long lastLaunch, final long now) {
+    if (lastLaunch <= 0) {
+      return -1;
+    }
+
+    if (now < GlobalConstants.BUILD_TIMESTAMP_MSEC) {
+      Logger.warn(LOG_TAG, "Current time " + now + " earlier than build date. Not calculating idle.");
+      return -1;
+    }
+
+    if (now < lastLaunch) {
+      Logger.warn(LOG_TAG, "Current time " + now + " earlier than last launch! Not calculating idle.");
+      return -1;
+    }
+
+    final long idleMillis = now - lastLaunch;
+    final int idleDays = (int) (idleMillis / MILLISECONDS_PER_DAY);
+
+    if (idleDays > AnnouncementsConstants.MAX_SANE_IDLE_DAYS) {
+      Logger.warn(LOG_TAG, "Idle from " + lastLaunch + " until " + now +
+                           ", which is insane. Not calculating idle.");
+      return -1;
+    }
+
+    return idleDays;
+  }
+
+  /**
+   * Return the number of days that we've been idle, assuming that we have a
+   * sane last launch time and the current time is within range. If no sane idle
+   * time can be returned, we return -1.
+   * The current time will be calculated from {@link System#currentTimeMillis()}.
+   *
+   * @param lastLaunch
+   *          Unix timestamp at which the browser was last launched.
+   * @return number of idle days, or -1 if out of range.
+   */
+  protected static int getIdleDays(final long lastLaunch) {
+    final long now = System.currentTimeMillis();
+    return getIdleDays(lastLaunch, now);
+  }
+
+  public static void fetchAnnouncements(URI uri, AnnouncementsFetchDelegate delegate) {
+    BaseResource r = new BaseResource(uri);
+    r.delegate = new AnnouncementsFetchResourceDelegate(r, delegate);
+    r.getBlocking();
+  }
+
+  /**
+   * Synchronous.
+   */
+  public static void fetchAndProcessAnnouncements(long lastLaunch,
+                                                  AnnouncementsFetchDelegate delegate) {
+    final long now = System.currentTimeMillis();
+    Logger.debug(LOG_TAG, "Fetching announcements. Last launch: " + lastLaunch + "; now: " + now);
+    try {
+      final String base = delegate.getServiceURL();
+      final URI uri = getAnnounceURI(base, lastLaunch);
+      Logger.info(LOG_TAG, "Fetching announcements from " + uri.toASCIIString());
+      fetchAnnouncements(uri, delegate);
+    } catch (URISyntaxException e) {
+      Logger.warn(LOG_TAG, "Couldn't create URL.", e);
+      return;
+    }
+  }
+}