Mask the AccountManager{Future,Callback} with a simple Callback.

sync/android/java/src/org/chromium/sync/signin/AccountManagerDelegate.java

Index: sync/android/java/src/org/chromium/sync/signin/AccountManagerDelegate.java
diff --git a/sync/android/java/src/org/chromium/sync/signin/AccountManagerDelegate.java b/sync/android/java/src/org/chromium/sync/signin/AccountManagerDelegate.java
index cfbab3ebd5f8941fe86f706110148f869e168a0b..4cc32a10bbcdc0cf6dbb72f94b07dcdc645e238e 100644
--- a/sync/android/java/src/org/chromium/sync/signin/AccountManagerDelegate.java
+++ b/sync/android/java/src/org/chromium/sync/signin/AccountManagerDelegate.java
@@ -15,8 +15,21 @@ import android.os.Handler;
  * Wrapper around the Android account manager, to facilitate dependency injection during testing.
  */
 public interface AccountManagerDelegate {
+    /**
+     * A callback class that can be used to allow asynchronous methods.
+     */
+    interface Callback<T> {
+        void gotResult(T value);
+    }
+
+    /**
+     * Use the asynchronous getAccountsByType(String, Callback<Account[]>) instead.
+     */
+    @Deprecated
     Account[] getAccountsByType(String type);
 
+    void getAccountsByType(String type, Callback<Account[]> callback);
+
     AccountManagerFuture<Bundle> getAuthToken(Account account, String authTokenType,
             boolean notifyAuthFailure, AccountManagerCallback<Bundle> callback, Handler handler);
 
@@ -24,6 +37,5 @@ public interface AccountManagerDelegate {
 
     AuthenticatorDescription[] getAuthenticatorTypes();
 
-    AccountManagerFuture<Boolean> hasFeatures(Account account, String[] features,
-            AccountManagerCallback<Boolean> callback, Handler handler);
+    void hasFeatures(Account account, String[] features, Callback<Boolean> callback);
 }