[Android O] Initialize channels on first launch/upgrade

chrome/android/java/src/org/chromium/chrome/browser/notifications/NotificationManagerProxyImpl.java

Index: chrome/android/java/src/org/chromium/chrome/browser/notifications/NotificationManagerProxyImpl.java
diff --git a/chrome/android/java/src/org/chromium/chrome/browser/notifications/NotificationManagerProxyImpl.java b/chrome/android/java/src/org/chromium/chrome/browser/notifications/NotificationManagerProxyImpl.java
index 46d2a103ce07b3e821cd369ceaa0366c47709b0d..f7092994130e4b2fd3b0c231cbb89be10f68be90 100644
--- a/chrome/android/java/src/org/chromium/chrome/browser/notifications/NotificationManagerProxyImpl.java
+++ b/chrome/android/java/src/org/chromium/chrome/browser/notifications/NotificationManagerProxyImpl.java
@@ -14,6 +14,8 @@ import org.chromium.base.Log;
 import java.lang.reflect.Constructor;
 import java.lang.reflect.InvocationTargetException;
 import java.lang.reflect.Method;
+import java.util.ArrayList;
+import java.util.List;
 
 /**
  * Default implementation of the NotificationManagerProxy, which passes through all calls to the
@@ -112,6 +114,52 @@ public class NotificationManagerProxyImpl implements NotificationManagerProxy {
     }
 
     @Override
+    public List<String> getNotificationChannelIds() {
+        assert BuildInfo.isAtLeastO();
+        List<String> channelIds = new ArrayList<>();
+        /*
+        The code in the try-block uses reflection in order to compile as it calls APIs newer than
+        our compileSdkVersion of Android. The equivalent code without reflection looks like this:
+
+            List<NotificationChannel> list = mNotificationManager.getNotificationChannels();
+            for (NotificationChannel channel : list) {
+                channelIds.add(channel.getId());
+            }
+         */
+        // TODO(crbug.com/707804) Stop using reflection once compileSdkVersion is high enough.
+        try {
+            Method method = mNotificationManager.getClass().getMethod("getNotificationChannels");
+            List channelsList = (List) method.invoke(mNotificationManager);
+            for (Object o : channelsList) {
+                Method getId = o.getClass().getMethod("getId");
+                channelIds.add((String) getId.invoke(o));
+            }
+        } catch (NoSuchMethodException | IllegalAccessException | InvocationTargetException e) {
+            Log.e(TAG, "Error getting notification channels:", e);
+        }
+        return channelIds;
+    }
+
+    @Override
+    public void deleteNotificationChannel(@ChannelsInitializer.ChannelId String id) {
+        assert BuildInfo.isAtLeastO();
+        /*
+        The code in the try-block uses reflection in order to compile as it calls APIs newer than
+        our compileSdkVersion of Android. The equivalent code without reflection looks like this:
+
+            mNotificationManager.deleteNotificationChannel(id);
+         */
+        // TODO(crbug.com/707804) Stop using reflection once compileSdkVersion is high enough.
+        try {
+            Method method = mNotificationManager.getClass().getMethod(
+                    "deleteNotificationChannel", String.class);
+            method.invoke(mNotificationManager, id);
+        } catch (NoSuchMethodException | IllegalAccessException | InvocationTargetException e) {
+            Log.e(TAG, "Error deleting notification channel:", e);
+        }
+    }
+
+    @Override
     public void notify(int id, Notification notification) {
         mNotificationManager.notify(id, notification);
     }