debugger: Indent on more than just Save
debugger: Indent on more than just Save

This is actually a tiny CL, but git/rietveld diffing is a fail.

This CL just modifies _addDepth() to handle savelayer and begin/endpicture.

Screenshot:

  https://screenshot.googleplex.com/NMdZZ9FQK1r.png

BUG=skia:
R=joshualitt@google.com, ethannicholas@google.com

Review URL: https://codereview.chromium.org/1694523002

google/skia-buildbot,google/skia-buildbot,google/skia-buildbot,google/skia-buildbot,google/skia-buildbot,google/skia-buildbot,google/skia-buildbot,google/skia-buildbot