As part of the Blink rewrite to match Chromium style, all enums will
be changed to have a 'k' prefix. The goal of this CL is to land one
of these changes ahead of time, since the automated tool doesn't
handle rewriting symbols that are declared in generated code.

BUG=678974
CQ_INCLUDE_TRYBOTS=master.tryserver.chromium.linux:linux_layout_tests_slimming_paint_v2

Review-Url: https://codereview.chromium.org/2614883007
Cr-Commit-Position: refs/heads/master@{#442156}