🐛 Validator: support decimals for intrisic sizer dimensions

[sebastianbenz]

This also fixes hard coded image dimensions.

Fixes #27528

[amp-owners-bot]

Hey @ampproject/wg-caching, these files were changed:

validator/testdata/transformed_feature_tests/server_side_rendering.html
validator/testdata/transformed_feature_tests/server_side_rendering.out
validator/validator-main.protoascii

[westonruter]

I just realized a way to make this more resilient to make this even more resilient to HTML mutations, perhaps the pattern should be modified like so:

value_regex: "data:image\\/svg\\+xml;charset=utf-8,<svg(\\s+(height=[\"']\\d+(\\.\\d+)?[\"']|width=[\"']\\d+(\\.\\d+)?[\"']|xmlns=[\"']http:\\/\\/www\\.w3\\.org\\/2000\\/svg[\"']|version=[\"']1\\.1[\"']))+\\s*(\\/>|></svg>)"

That would allow the order of the attributes to be modified freely. The whitespace would also be more forgiving. (It also combines the two patterns to use ['"] to represent the attributes. Granted this would allow something like width='1" causing a XML syntax error.) It also allows for a closing </svg> tag which actually should solve the problem of HTML minifiers from stripping self-closing slashes.

Regex without escaping:

data:image\/svg\+xml;charset=utf-8,<svg(\s+(height=["']\d+(\.\d+)?["']|width=["']\d+(\.\d+)?["']|xmlns=["']http:\/\/www\.w3\.org\/2000\/svg["']|version=["']1\.1["']))+\s*(\/>|></svg>)