GitLab

This change removes position from the GraphicsLayer tree dump format as
another step toward the complete removal of position from GraphicsLayer.
This is accomplished by intentionally passing through 0, 0 for the
offset/position to CCLayerAsJSON which results in no output for
position.

As a supporting change, this change also renames CCLayerAsJSON's
position parameter to be offset_from_transform_node which more
accurately reflects what it is intended to be.

Finally, removing a dead-code version of GetLayerTreeAsTextForTesting in
WebLocalFrameImpl.


Bug: 999336
Change-Id: I17f40076ec6bcf6cab9c70034c2466847af3c233
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1898806Reviewed-by: Philip Rogers <pdr@chromium.org>
Reviewed-by: Xianzhu Wang <wangxianzhu@chromium.org>
Commit-Queue: Sam Fortiner <samfort@microsoft.com>
Cr-Commit-Position: refs/heads/master@{#712926}