Merge "Always mutate child when added to drawable container" into nyc-dev

am: d1f686f5dc

* commit 'd1f686f5dcf33606cf1e83cf2f7b8e41f5bd9148':
  Always mutate child when added to drawable container

Change-Id: Ief6bbd8ab12d2e92dfc3a742c2acbed221c35a51

graphics/java/android/graphics/drawable/DrawableContainer.java

@@ -786,13 +786,19 @@ public class DrawableContainer extends Drawable implements Drawable.Callback {
             return mChangingConfigurations | mChildrenChangingConfigurations;
         }
 
+        /**
+         * Adds the drawable to the end of the list of contained drawables.
+         *
+         * @param dr the drawable to add
+         * @return the position of the drawable within the container
+         */
         public final int addChild(Drawable dr) {
             final int pos = mNumChildren;
-
             if (pos >= mDrawables.length) {
                 growArray(pos, pos+10);
             }
 
+            dr.mutate();
             dr.setVisible(false, true);
             dr.setCallback(mOwner);