Add more edge case tests for the JSONParser.

This increases code coverage based on what is observed in this report:
https://chromium-coverage.storage.googleapis.com/reports/558266_tests_only/linux/chromium/src/base/json/json_parser.cc.html

Bug: 489301
Change-Id: Ia7f9ef97e93fb92e440717d9463d810dab4f87dc
Reviewed-on: https://chromium-review.googlesource.com/1059717
Commit-Queue: Robert Sesek <rsesek@chromium.org>
Reviewed-by: Daniel Cheng <dcheng@chromium.org>
Cr-Commit-Position: refs/heads/master@{#559271}

CrOS-Libchrome-Original-Commit: ca2924782bd669bec96d387dd7e3ba2469a1d060
2 files changed
tree: af5f8a19594d5c623f89a91dce49b8cf898c0e20
  1. base/
  2. build/
  3. components/
  4. dbus/
  5. device/
  6. ipc/
  7. mojo/
  8. testing/
  9. third_party/
  10. ui/