[Android] Implement GetRuleIterator for channels provider

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

 // Copyright 2017 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.
 
 package org.chromium.chrome.browser.notifications;
 
 import org.chromium.base.BuildInfo;
 import org.chromium.base.annotations.CalledByNative;
 
 /**
@@ skipping 20 matching lines @@
         return false;
     }
 
     @CalledByNative
     static @NotificationChannelStatus int getChannelStatus(String origin) {
         // TODO(crbug.com/700377) Actually check channel status.
         return NotificationChannelStatus.UNAVAILABLE;
     }
 
     @CalledByNative
+    static SiteChannel[] getSiteChannels() {
+        // TODO(crbug.com/700377) Actually get site channels.
+        return new SiteChannel[] {};
+    }
+
+    @CalledByNative
     static void deleteChannel(String origin) {
         // TODO(crbug.com/700377) Actually delete channel.
     }
+
+    static class SiteChannel {
+        private final String mOrigin;
+        private final int mStatus;
+
+        private SiteChannel(String origin, int status) {
+            mOrigin = origin;
+            mStatus = status;
+        }
+
+        @CalledByNative("SiteChannel")
+        private String getOrigin() {
+            return mOrigin;
+        }
+
+        @CalledByNative("SiteChannel")
+        private int getStatus() {

[Peter Beverloo, 2017/06/02 15:14:26]

Should this (and `int status` in the member/constructor) be marked as
@NotificationChannelStatus

[awdf, 2017/06/02 16:59:48]

Done.

+            return mStatus;
+        }
+    }
 }