am 91a9c963: When initiating a drag and drop from a folder in home, you could sometimes see a black background behind the icon. This was due to uncleared drawing caches.

Merge commit '91a9c9636f10f1e12cd1f660b2e330634fbdc7dc'

* commit '91a9c9636f10f1e12cd1f660b2e330634fbdc7dc':
  When initiating a drag and drop from a folder in home, you could sometimes see

src/com/android/launcher/DragLayer.java

@@ -201,6 +201,9 @@ public class DragLayer extends FrameLayout implements DragController {
         int color = v.getDrawingCacheBackgroundColor();
         v.setDrawingCacheBackgroundColor(0);
 
+        if (color != 0) {
+            v.destroyDrawingCache();
+        }
         v.buildDrawingCache();
         Bitmap viewBitmap = v.getDrawingCache();
         int width = viewBitmap.getWidth();