Teach AssetAtlas about more drawables

Bug: 18317479

Change-Id: I16868ee204d24af72af9a2efc987f7e9eb1d266b

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

@@ -20,6 +20,7 @@ import android.annotation.NonNull;
 import android.content.res.ColorStateList;
 import android.content.res.Resources;
 import android.content.res.Resources.Theme;
+import android.graphics.Bitmap;
 import android.graphics.Canvas;
 import android.graphics.ColorFilter;
 import android.graphics.Insets;
@@ -31,6 +32,8 @@ import android.os.SystemClock;
 import android.util.LayoutDirection;
 import android.util.SparseArray;
 
+import java.util.Collection;
+
 /**
  * A helper class that contains several {@link Drawable}s and selects which one to use.
  *
@@ -1062,6 +1065,20 @@ public class DrawableContainer extends Drawable implements Drawable.Callback {
             return true;
         }
 
+        /** @hide */
+        @Override
+        public int addAtlasableBitmaps(Collection<Bitmap> atlasList) {
+            final int N = mNumChildren;
+            int pixelCount = 0;
+            for (int i = 0; i < N; i++) {
+                final ConstantState state = getChild(i).getConstantState();
+                if (state != null) {
+                    pixelCount += state.addAtlasableBitmaps(atlasList);
+                }
+            }
+            return pixelCount;
+        }
+
         /**
          * Class capable of cloning a Drawable from another Drawable's
          * ConstantState.