GitLab

This patch changes the names of functions as follows:
PaintOpBuffer::approximateBytesUsed -> bytes_used
PaintOpBuffer::approximateOpCount -> size

Also changes related functions in other classes where appropriate.
Also changes the return type of new size function to be size_t.

R=enne@chromium.org, danakj@chromium.org
CQ_INCLUDE_TRYBOTS=master.tryserver.blink:linux_trusty_blink_rel;master.tryserver.chromium.linux:linux_layout_tests_slimming_paint_v2

Review-Url: https://codereview.chromium.org/2884563004
Cr-Commit-Position: refs/heads/master@{#472259}