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This CL is adding special handling for the the control codepoints
(block C0). Previously, only the control character \n was
replaced by its visual symbols. Other control characters
are not handled by ShapeRuns which is leading to expensive
fallback fonts calls. (see http://crbug.com/993100)

Control codes:
  https://en.wikipedia.org/wiki/C0_and_C1_control_codes

The symbols used to display these control characters:
  https://www.compart.com/en/unicode/block/U+2400

Bug: 1011818, 1014119
Change-Id: I924dcb13c9e0e11d321ef375cd4285432aaf6cab
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1863394
Commit-Queue: Etienne Bergeron <etienneb@chromium.org>
Reviewed-by: Alexei Svitkine <asvitkine@chromium.org>
Reviewed-by: Robert Liao <robliao@chromium.org>
Reviewed-by: Michael Wasserman <msw@chromium.org>
Cr-Commit-Position: refs/heads/master@{#707401}