Track client debug names for raster invalidation tracking

This reduces differences of layout test results of spv2, and
also makes spv2 paint invalidation output more meaningful.

BUG=644358
CQ_INCLUDE_TRYBOTS=master.tryserver.chromium.linux:linux_layout_tests_slimming_paint_v2

Review-Url: https://codereview.chromium.org/2876923002
Cr-Commit-Position: refs/heads/master@{#471322}
6 files changed