Add the gtest pretty printer for ResourceError

This will be used by https://codereview.chromium.org/1257343003/.

This CL ignores a presubmit error:
  "Streams are highly discouraged.  [readability/streams]"
  in PlatformTestPrinters.cpp.
Because:
  std::ostream is required for gtest pretty printing.
BUG=532364

Review URL: https://codereview.chromium.org/1722893002

Cr-Commit-Position: refs/heads/master@{#381034}
3 files changed