reject unhandled key events if browser is paused

http://b/2532511

Change-Id: Idd08b90d3a5dec61c9328eecda834f2fcc7d16f5
diff --git a/src/com/android/browser/Tab.java b/src/com/android/browser/Tab.java
index e78fa45..a5dc975 100644
--- a/src/com/android/browser/Tab.java
+++ b/src/com/android/browser/Tab.java
@@ -801,7 +801,7 @@
 
         @Override
         public void onUnhandledKeyEvent(WebView view, KeyEvent event) {
-            if (!mInForeground) {
+            if (!mInForeground || mActivity.mActivityInPause) {
                 return;
             }
             if (event.isDown()) {