Porting DTMF post dial wait feature.

Bug: 10459289
Change-Id: Ib279fcdf71857abae218b70081f7da569901d80c
diff --git a/src/com/android/phone/DTMFTonePlayer.java b/src/com/android/phone/DTMFTonePlayer.java
index d3ed53e..0acd114 100644
--- a/src/com/android/phone/DTMFTonePlayer.java
+++ b/src/com/android/phone/DTMFTonePlayer.java
@@ -31,8 +31,6 @@
 import com.android.internal.telephony.PhoneConstants;
 import com.android.services.telephony.common.Call;
 
-import java.util.ArrayList;
-import java.util.HashMap;
 import java.util.LinkedList;
 import java.util.List;
 import java.util.Map;
@@ -125,6 +123,11 @@
         checkCallState();
     }
 
+    @Override
+    public void onPostDialWait(int callId, String chars) {
+        // no-op
+    }
+
     /**
      * Allocates some resources we keep around during a "dialer session".
      *