Update the download summary icon

chrome/android/java/src/org/chromium/chrome/browser/download/DownloadNotificationService.java

Index: chrome/android/java/src/org/chromium/chrome/browser/download/DownloadNotificationService.java
diff --git a/chrome/android/java/src/org/chromium/chrome/browser/download/DownloadNotificationService.java b/chrome/android/java/src/org/chromium/chrome/browser/download/DownloadNotificationService.java
index 979b2ba628be529f56c999ee86db0770b2dea8c2..d3da69c8270e8c4783452f99501b4bf034ae8d3e 100644
--- a/chrome/android/java/src/org/chromium/chrome/browser/download/DownloadNotificationService.java
+++ b/chrome/android/java/src/org/chromium/chrome/browser/download/DownloadNotificationService.java
@@ -23,9 +23,11 @@ import android.graphics.Rect;
 import android.graphics.drawable.shapes.OvalShape;
 import android.os.Binder;
 import android.os.Build;
+import android.os.Bundle;
 import android.os.IBinder;
 import android.service.notification.StatusBarNotification;
 import android.text.TextUtils;
+import android.util.Pair;
 
 import org.chromium.base.ApiCompatibilityUtils;
 import org.chromium.base.ApplicationStatus;
@@ -59,7 +61,7 @@ import java.util.concurrent.TimeUnit;
  *
  * On O and above, this service will receive {@link Service#startForeground(int, Notification)}
  * calls when containing active downloads.  The foreground notification will be the summary
- * notification generated by {@link DownloadNotificationService#getSummaryNotification(Context)}.
+ * notification generated by {@link DownloadNotificationService#buildSummaryNotification(Context)}.
  * The service will receive a {@link Service#stopForeground(boolean)} call when all active downloads
  * are paused.  The summary notification will be hidden when there are no other notifications in the
  * {@link NotificationConstants#GROUP_DOWNLOADS} group.  This gets checked after every notification
@@ -93,6 +95,8 @@ public class DownloadNotificationService extends Service {
 
     /** Notification Id starting value, to avoid conflicts from IDs used in prior versions. */
 
+    private static final String EXTRA_NOTIFICATION_BUNDLE_ICON_ID =
+            "Chrome.NotificationBundleIconIdExtra";
     private static final int STARTING_NOTIFICATION_ID = 1000000;
     private static final int MAX_RESUMPTION_ATTEMPT_LEFT = 5;
     @VisibleForTesting static final long SECONDS_PER_MINUTE = TimeUnit.MINUTES.toSeconds(1);
@@ -145,7 +149,7 @@ public class DownloadNotificationService extends Service {
         intent.setComponent(new ComponentName(context, DownloadNotificationService.class));
 
         if (BuildInfo.isAtLeastO()) {
-            Notification notification = getSummaryNotification(context);
+            Notification notification = buildSummaryNotification(context);
 
             AppHooks.get().startServiceWithNotification(
                     intent, NotificationConstants.NOTIFICATION_ID_DOWNLOAD_SUMMARY, notification);
@@ -155,16 +159,101 @@ public class DownloadNotificationService extends Service {
     }
 
     /**
-     * Builds a summary notification that represents downloads.  This is the notification passed to
-     * {@link #startForeground(int, Notification)}, which keeps this service in the foreground.
-     * @param context The context used to build the notification and pull specific resources.
-     * @return The {@link Notification} to show for the summary.  Meant to be used by
-     *         {@link NotificationManager#notify(int, Notification)}.
+     * Calculates the suggested icon for the summary notification based on the other notifications
+     * currently showing.
+     * @param context A context to use to query Android-specific information (NotificationManager).
+     * @param removedNotificationId The id of a notification that is currently closing and should be
+     *                              ignored.  -1 if no notifications are being closed.
+     * @param addedNotification     A {@link Pair} of <id, Notification> of a notification that is
+     *                              currently being added and should be used in addition to or in
+     *                              place of the existing icons.
+     * @return                      A {@link Pair} that represents both whether or not the new icon
+     *                              is different from the old one and the icon id itself.
+     */
+    @TargetApi(Build.VERSION_CODES.M)
+    private static Pair<Boolean, Integer> getSummaryIcon(Context context, int removedNotificationId,
+            Pair<Integer, Notification> addedNotification) {
+        if (!BuildInfo.isAtLeastO()) return new Pair<Boolean, Integer>(false, -1);
+        boolean progress = false;
+        boolean paused = false;
+        boolean pending = false;
+        boolean completed = false;
+        boolean failed = false;
+
+        final int progressIcon = android.R.drawable.stat_sys_download;
+        final int pausedIcon = R.drawable.ic_download_pause;
+        final int pendingIcon = R.drawable.ic_download_pending;
+        final int completedIcon = R.drawable.offline_pin;
+        final int failedIcon = android.R.drawable.stat_sys_download_done;
+
+        NotificationManager manager =
+                (NotificationManager) context.getSystemService(Context.NOTIFICATION_SERVICE);
+        StatusBarNotification[] notifications = manager.getActiveNotifications();
+
+        int oldIcon = -1;
+        for (StatusBarNotification notification : notifications) {
+            boolean isDownloadsGroup = TextUtils.equals(notification.getNotification().getGroup(),
+                    NotificationConstants.GROUP_DOWNLOADS);
+            if (!isDownloadsGroup) continue;
+            if (notification.getId() == removedNotificationId) continue;
+
+            boolean isSummaryNotification =
+                    notification.getId() == NotificationConstants.NOTIFICATION_ID_DOWNLOAD_SUMMARY;
+
+            if (addedNotification != null && addedNotification.first == notification.getId())
+                continue;
+
+            int icon =
+                    notification.getNotification().extras.getInt(EXTRA_NOTIFICATION_BUNDLE_ICON_ID);
+            if (isSummaryNotification) {
+                oldIcon = icon;
+                continue;
+            }
+
+            progress |= icon == progressIcon;
+            paused |= icon == pausedIcon;
+            pending |= icon == pendingIcon;
+            completed |= icon == completedIcon;
+            failed |= icon == failedIcon;
+        }
+
+        if (addedNotification != null) {
+            int icon = addedNotification.second.extras.getInt(EXTRA_NOTIFICATION_BUNDLE_ICON_ID);
+
+            progress |= icon == progressIcon;
+            paused |= icon == pausedIcon;
+            pending |= icon == pendingIcon;
+            completed |= icon == completedIcon;
+            failed |= icon == failedIcon;
+        }
+
+        int newIcon = android.R.drawable.stat_sys_download_done;
+        if (progress) {
+            newIcon = android.R.drawable.stat_sys_download;
+        } else if (paused) {
+            newIcon = R.drawable.ic_download_pause;
+        } else if (pending) {
+            newIcon = R.drawable.ic_download_pending;
+        } else if (completed) {
+            newIcon = R.drawable.offline_pin;
+        } else if (failed) {
+            newIcon = android.R.drawable.stat_sys_download_done;
+        }
+        return new Pair<Boolean, Integer>(newIcon != oldIcon, newIcon);
+    }
+
+    /**
+     * Builds a summary notification that represents all downloads.
+     * {@see #buildSummaryNotification(Context)}.
+     * @param context A context used to query Android strings and resources.
+     * @param iconId  The id of an icon to use for the notification.
+     * @return        a {@link Notification} that represents the summary icon for all downloads.
      */
-    private static Notification getSummaryNotification(Context context) {
+    private static Notification buildSummaryNotificationWithIcon(Context context, int iconId) {
         String title =
                 context.getResources().getString(R.string.download_notification_summary_title,
                         DownloadSharedPreferenceHelper.getInstance().getEntries().size());
+
         ChromeNotificationBuilder builder =
                 AppHooks.get()
                         .createChromeNotificationBuilder(true /* preferCompat */,
@@ -173,10 +262,13 @@ public class DownloadNotificationService extends Service {
                                 NotificationConstants.CATEGORY_GROUP_ID_GENERAL,
                                 context.getString(R.string.notification_category_group_general))
                         .setContentTitle(title)
-                        .setSmallIcon(android.R.drawable.stat_sys_download_done)
+                        .setSmallIcon(iconId)
                         .setLocalOnly(true)
                         .setGroup(NotificationConstants.GROUP_DOWNLOADS)
                         .setGroupSummary(true);
+        Bundle extras = new Bundle();
+        extras.putInt(EXTRA_NOTIFICATION_BUNDLE_ICON_ID, iconId);
+        builder.addExtras(extras);
 
         // This notification should not actually be shown.  But if it is, set the click intent to
         // open downloads home.
@@ -190,6 +282,18 @@ public class DownloadNotificationService extends Service {
     }
 
     /**
+     * Builds a summary notification that represents downloads.  This is the notification passed to
+     * {@link #startForeground(int, Notification)}, which keeps this service in the foreground.
+     * @param context The context used to build the notification and pull specific resources.
+     * @return The {@link Notification} to show for the summary.  Meant to be used by
+     *         {@link NotificationManager#notify(int, Notification)}.
+     */
+    private static Notification buildSummaryNotification(Context context) {
+        Pair<Boolean, Integer> icon = getSummaryIcon(context, -1, null);
+        return buildSummaryNotificationWithIcon(context, icon.second);
+    }
+
+    /**
      * @return Whether or not there are any current resumable downloads being tracked.  These
      *         tracked downloads may not currently be showing notifications.
      */
@@ -305,12 +409,12 @@ public class DownloadNotificationService extends Service {
 
     /**
      * On >= O Android releases, puts this service into a foreground state, binding it to the
-     * {@link Notification} generated by {@link #getSummaryNotification(Context)}.
+     * {@link Notification} generated by {@link #buildSummaryNotification(Context)}.
      */
     @VisibleForTesting
     void startForegroundInternal() {
         if (!BuildInfo.isAtLeastO()) return;
-        Notification notification = getSummaryNotification(getApplicationContext());
+        Notification notification = buildSummaryNotification(getApplicationContext());
         startForeground(NotificationConstants.NOTIFICATION_ID_DOWNLOAD_SUMMARY, notification);
     }
 
@@ -441,6 +545,30 @@ public class DownloadNotificationService extends Service {
     }
 
     /**
+     * Updates the notification summary with a new icon, if necessary.
+     * @param removedNotificationId The id of a notification that is currently closing and should be
+     *                              ignored.  -1 if no notifications are being closed.
+     * @param addedNotification     A {@link Pair} of <id, Notification> of a notification that is
+     *                              currently being added and should be used in addition to or in
+     *                              place of the existing icons.
+     */
+    @VisibleForTesting
+    void updateSummaryIcon(
+            int removedNotificationId, Pair<Integer, Notification> addedNotification) {
+        if (!BuildInfo.isAtLeastO()) return;
+
+        Pair<Boolean, Integer> icon =
+                getSummaryIcon(mContext, removedNotificationId, addedNotification);
+
+        // Avoid rebuilding the summary notification if the icon hasn't changed or we have (or are
+        // about to have) no active downloads.
+        if (!icon.first || !hasDownloadNotifications(removedNotificationId)) return;
+
+        mNotificationManager.notify(NotificationConstants.NOTIFICATION_ID_DOWNLOAD_SUMMARY,
+                buildSummaryNotificationWithIcon(mContext, icon.second));
+    }
+
+    /**
      * Cancels the existing summary notification.  Moved to a helper method for test mocking.
      */
     @VisibleForTesting
@@ -460,11 +588,11 @@ public class DownloadNotificationService extends Service {
      *                               Or pass {@code null} if no notification fits that criteria.
      */
     @TargetApi(Build.VERSION_CODES.M)
-    void hideSummaryNotificationIfNecessary(Integer notificationIdToIgnore) {
-        if (!BuildInfo.isAtLeastO()) return;
-        if (mDownloadsInProgress.size() > 0) return;
+    boolean hideSummaryNotificationIfNecessary(Integer notificationIdToIgnore) {
+        if (!BuildInfo.isAtLeastO()) return false;
+        if (mDownloadsInProgress.size() > 0) return false;
 
-        if (hasDownloadNotifications(notificationIdToIgnore)) return;
+        if (hasDownloadNotifications(notificationIdToIgnore)) return false;
 
         StatusBarNotification notification = getSummaryNotification();
         if (notification != null) {
@@ -495,6 +623,7 @@ public class DownloadNotificationService extends Service {
         // Stop the service which should start the destruction process.  At this point we should be
         // (1) a background service and (2) unbound from any clients.
         stopSelf();
+        return true;
     }
 
     @Override
@@ -654,7 +783,9 @@ public class DownloadNotificationService extends Service {
         // down, don't stop foreground if we have no download notifications left to show.  Hiding
         // the summary will take care of that for us.
         stopTrackingInProgressDownload(downloadGuid, hasDownloadNotifications(notificationId));
-        hideSummaryNotificationIfNecessary(notificationId);
+        if (!hideSummaryNotificationIfNecessary(notificationId)) {
+            updateSummaryIcon(notificationId, null);
+        }
     }
 
     /**
@@ -834,6 +965,9 @@ public class DownloadNotificationService extends Service {
      */
     private ChromeNotificationBuilder buildNotification(
             int iconId, String title, String contentText) {
+        Bundle extras = new Bundle();
+        extras.putInt(EXTRA_NOTIFICATION_BUNDLE_ICON_ID, iconId);
+
         ChromeNotificationBuilder builder =
                 AppHooks.get()
                         .createChromeNotificationBuilder(true /* preferCompat */,
@@ -847,7 +981,8 @@ public class DownloadNotificationService extends Service {
                         .setLocalOnly(true)
                         .setAutoCancel(true)
                         .setContentText(contentText)
-                        .setGroup(NotificationConstants.GROUP_DOWNLOADS);
+                        .setGroup(NotificationConstants.GROUP_DOWNLOADS)
+                        .addExtras(extras);
         return builder;
     }
 
@@ -1061,6 +1196,7 @@ public class DownloadNotificationService extends Service {
         } else {
             mDownloadSharedPreferenceHelper.removeSharedPreferenceEntry(downloadGuid);
         }
+        updateSummaryIcon(-1, new Pair<Integer, Notification>(id, notification));
     }
 
     private void trackNotificationUma(boolean isOfflinePage, String downloadGuid) {