Specify the HTML document’s encoding (#2158)
Specify the HTML document’s encoding (#2158)

This avoids rendering non-ASCII symbols as mojibake.

Fixes: https://bugs.chromium.org/p/chromium/issues/detail?id=920160
google/clusterfuzz,google/clusterfuzz,google/clusterfuzz,google/clusterfuzz,google/clusterfuzz,google/clusterfuzz,google/clusterfuzz,google/clusterfuzz