Add the ability to autoStart AID from xml

am: 1dd88daf92

Change-Id: I01fc7e34b4e2909f6984b9266e237f3cc9f08432

core/res/res/values/attrs.xml

@@ -5968,6 +5968,9 @@
              in the encoded data. Setting this to infinite (-1) will result in the
              animation repeating as long as it is displayed (once start() is called). -->
         <attr name="repeatCount"/>
+        <!-- When true, automatically start animating. The default is false, meaning
+             that the animation will not start until start() is called. -->
+        <attr name="autoStart" />
     </declare-styleable>
 
     <!-- Drawable used to draw bitmaps. -->

graphics/java/android/graphics/drawable/AnimatedImageDrawable.java

@@ -261,6 +261,12 @@ public class AnimatedImageDrawable extends Drawable implements Animatable2 {
         if (repeatCount != REPEAT_UNDEFINED) {
             this.setRepeatCount(repeatCount);
         }
+
+        boolean autoStart = a.getBoolean(
+                R.styleable.AnimatedImageDrawable_autoStart, false);
+        if (autoStart && mState.mNativePtr != 0) {
+            this.start();
+        }
     }
 
     /**