Refactor: Inline AndroidSyncSettingsChangedObserver with anonymous class

This class was used in a single place (to observe auto-sync settings via
Android APIs), its name was very similar to the exposed
AndroidSyncSettingsObserver interface, and its documentation was wrong
(it treated it as AndroidSyncSettingsObserver). The CL removes the class
and uses an anonymous class instead.

Bug: None
Change-Id: I73af1acf74b90d50e7412a50b1097668a1cfe17d
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2403462Reviewed-by: Marc Treib <treib@chromium.org>
Commit-Queue: Victor Vianna <victorvianna@google.com>
Cr-Commit-Position: refs/heads/master@{#805733}

chrome/android/java/src/org/chromium/chrome/browser/sync/AndroidSyncSettings.java

@@ -118,8 +118,18 @@ public class AndroidSyncSettings {
         updateSyncability(callback);
 
         mSyncContentResolverDelegate.addStatusChangeListener(
-                ContentResolver.SYNC_OBSERVER_TYPE_SETTINGS,
-                new AndroidSyncSettingsChangedObserver());
+                ContentResolver.SYNC_OBSERVER_TYPE_SETTINGS, new SyncStatusObserver() {
+                    @Override
+                    public void onStatusChanged(int which) {
+                        if (which == ContentResolver.SYNC_OBSERVER_TYPE_SETTINGS) {
+                            // Sync settings have changed; update our cached values.
+                            if (updateCachedSettings()) {
+                                // If something actually changed, tell our observers.
+                                notifyObservers();
+                            }
+                        }
+                    }
+                });
     }
 
     /**
@@ -286,24 +296,6 @@ public class AndroidSyncSettings {
         });
     }
 
-    /**
-     * Helper class to be used by observers whenever sync settings change.
-     *
-     * To register the observer, call AndroidSyncSettings.registerObserver(...).
-     */
-    private class AndroidSyncSettingsChangedObserver implements SyncStatusObserver {
-        @Override
-        public void onStatusChanged(int which) {
-            if (which == ContentResolver.SYNC_OBSERVER_TYPE_SETTINGS) {
-                // Sync settings have changed; update our cached values.
-                if (updateCachedSettings()) {
-                    // If something actually changed, tell our observers.
-                    notifyObservers();
-                }
-            }
-        }
-    }
-
     /**
      * Update the three cached settings from the content resolver.
      *