Support fallback key events

 Bug: 6023055

Change-Id: Ifc36425d6b09d0938f7e08176a749159c27fe088
diff --git a/src/com/android/browser/PreloadController.java b/src/com/android/browser/PreloadController.java
index 0efe119..66b89f4 100644
--- a/src/com/android/browser/PreloadController.java
+++ b/src/com/android/browser/PreloadController.java
@@ -130,8 +130,9 @@
     }
 
     @Override
-    public void onUnhandledKeyEvent(KeyEvent event) {
+    public boolean onUnhandledKeyEvent(KeyEvent event) {
         if (LOGD_ENABLED) Log.d(LOGTAG, "onUnhandledKeyEvent()");
+        return false;
     }
 
     @Override