blink: Reduce the size of thread_state.h.

Remove web_thread.h #include from thread_state.h.

thread_state.h is used in 6000+ compilation units, and this CL reduces
its estimated expanded size from 1,284KB to 937KB.

Bug: 242216
Cq-Include-Trybots: luci.chromium.try:linux_layout_tests_slimming_paint_v2;master.tryserver.blink:linux_trusty_blink_rel
Change-Id: If0971d1b069e4bab55a1c1b51fe31514fa32c7c1
Reviewed-on: https://chromium-review.googlesource.com/1102223
Reviewed-by: Keishi Hattori <keishi@chromium.org>
Reviewed-by: Kentaro Hara <haraken@chromium.org>
Commit-Queue: Kent Tamura <tkent@chromium.org>
Cr-Commit-Position: refs/heads/master@{#567581}
16 files changed