Tile chat background.

app/src/main/res/drawable/chat_background_repeat.xml

+<?xml version="1.0" encoding="utf-8"?>
+<bitmap
+    xmlns:android="http://schemas.android.com/apk/res/android"
+    android:src="@drawable/chat_background"
+    android:tileMode="repeat"
+    android:dither="true" />
\ No newline at end of file

app/src/main/res/layout/chat_viewer_item.xml

@@ -17,6 +17,7 @@
     android:orientation="vertical"
     android:layout_width="match_parent"
     android:layout_height="match_parent"
+    android:background="@drawable/chat_background_repeat"
     >
     <ListView
         android:id="@android:id/list"