Add position information for DrawViews.

Summary: Previously, we had no information about the positioning of the view until after we had attached it.  We have the position information attached to the shadow node, but this attaches it to the DrawView as well.  It also removes the need for AbstractClippingDrawCommand.

Reviewed By: ahmedre

Differential Revision: D3609092

ReactAndroid/src/main/java/com/facebook/react/flat/StateBuilder.java

@@ -536,6 +536,10 @@ import com.facebook.react.uimanager.events.EventDispatcher;
       addNativeChild(node);
       if (!parentIsAndroidView) {
         mDrawCommands.add(node.collectDrawView(
+            left,
+            top,
+            right,
+            bottom,
             parentClipLeft,
             parentClipTop,
             parentClipRight,
@@ -544,8 +548,8 @@ import com.facebook.react.uimanager.events.EventDispatcher;
 
       updated = collectStateForMountableNode(
           node,
-          left - left,
-          top - top,
+          0, // left - left
+          0, // top - top
           right - left,
           bottom - top,
           parentClipLeft - left,