Added the no-arg add() widget method to the HTMLPanel.

Review at http://gwt-code-reviews.appspot.com/1226801

Review by: rjrjr@google.com

git-svn-id: https://google-web-toolkit.googlecode.com/svn/trunk@9462 8db76d5a-ed1c-0410-87a9-c151d255dfc7
diff --git a/user/src/com/google/gwt/user/client/ui/HTMLPanel.java b/user/src/com/google/gwt/user/client/ui/HTMLPanel.java
index e528523..814381a 100644
--- a/user/src/com/google/gwt/user/client/ui/HTMLPanel.java
+++ b/user/src/com/google/gwt/user/client/ui/HTMLPanel.java
@@ -102,6 +102,16 @@
   }
   
   /**
+   * Adds a child widget to the panel.
+   * 
+   * @param widget the widget to be added
+   */
+  @Override
+  public void add(Widget widget) {
+    add(widget, getElement());
+  }
+
+  /**
    * Adds a child widget to the panel, contained within the HTML element
    * specified by a given id.
    * 
diff --git a/user/test/com/google/gwt/user/client/ui/HTMLPanelTest.java b/user/test/com/google/gwt/user/client/ui/HTMLPanelTest.java
index 02ba0ad..94f63ae 100644
--- a/user/test/com/google/gwt/user/client/ui/HTMLPanelTest.java
+++ b/user/test/com/google/gwt/user/client/ui/HTMLPanelTest.java
@@ -45,6 +45,23 @@
   }
 
   /**
+   * Tests {@link HTMLPanel#add(Widget)}.
+   */
+  public void testAdd() {
+    Label labelA = new Label("A");
+    Label labelB = new Label("B");
+    HTMLPanel p = new HTMLPanel("<div></div>");
+    p.add(labelA);
+    p.add(labelB);
+
+    // Ensure that both Labels have the correct parent.
+    Element first = p.getElement().getFirstChildElement();
+    assertSame(labelA.getElement(), first.getNextSiblingElement());
+    assertSame(labelB.getElement(), labelA.getElement().getNextSiblingElement());
+    assertNull(labelB.getElement().getNextSiblingElement());
+  }
+
+  /**
    * Tests {@link HTMLPanel#add(Widget, String)}.
    */
   public void testAddToElementWithId() {