Add new CAPTURE_LAYERS command to HiearchyViewer protocol.

This command is used by the desktop tool to export a given view hierarchy into
a layered file format.
diff --git a/core/java/android/view/View.java b/core/java/android/view/View.java
index 639441b..abbab0e 100644
--- a/core/java/android/view/View.java
+++ b/core/java/android/view/View.java
@@ -6493,7 +6493,7 @@
      * Create a snapshot of the view into a bitmap.  We should probably make
      * some form of this public, but should think about the API.
      */
-    Bitmap createSnapshot(Bitmap.Config quality, int backgroundColor) {
+    Bitmap createSnapshot(Bitmap.Config quality, int backgroundColor, boolean skipChildren) {
         int width = mRight - mLeft;
         int height = mBottom - mTop;