Merge third_party/skia/src from https://chromium.googlesource.com/external/skia/src.git at da6ca64e5135eecbc58eea38a2f1e227152d085e

This commit was generated by merge_from_chromium.py.

Change-Id: I9946a8a144b1dca519e556109fc4b1eecaddf1d4