Save the matrix as well when doing a saveLayer() for filters.

This is necessary so that the matrix is correctly restored before
filter application.  Since adding this flag is equivalent to setting
all the flags, just use kARGB_ClipLayer_SaveFlag instead.

BUG=337831
R=fmalita@chromium.org

Review URL: https://codereview.chromium.org/177073012

git-svn-id: svn://svn.chromium.org/blink/trunk@167814 bbb929c8-8fbe-4397-9dbb-9b2b20218538