Add missing getBackColor() override to RichTextAreaImplMozilla.

Fixes issue 3262.

Review-Link: http://gwt-code-reviews.appspot.com/1662803/

Review by: goktug@google.com

git-svn-id: https://google-web-toolkit.googlecode.com/svn/trunk@11479 8db76d5a-ed1c-0410-87a9-c151d255dfc7
diff --git a/user/src/com/google/gwt/user/client/ui/impl/RichTextAreaImplMozilla.java b/user/src/com/google/gwt/user/client/ui/impl/RichTextAreaImplMozilla.java
index 3593855..fe3bbcb 100644
--- a/user/src/com/google/gwt/user/client/ui/impl/RichTextAreaImplMozilla.java
+++ b/user/src/com/google/gwt/user/client/ui/impl/RichTextAreaImplMozilla.java
@@ -27,6 +27,11 @@
   boolean isFirstFocus;
 
   @Override
+  public String getBackColor() {
+    return queryCommandValue("HiliteColor");
+  }
+
+  @Override
   public native void initElement() /*-{
     // Mozilla doesn't allow designMode to be set reliably until the iframe is
     // fully loaded.