This error is raised on many Win system, when generating file "WebKit\WebKitBuild\obj\WebCore\DerivedSources\CSSValueKeywords.h", script file "WebKit\WebCore\css\makevalues.pl" filed to process "ox0D0A" problem, it just chomp one character "ox0A", so, any blank line, in "CSSValueKeywords.in", is generated a string "CSSValueox0D = xxxx". A ugly patch is to modify "makevalues.pl", line 'next if ($_ eq "")' to 'next if ($_ eq || $_ eq "\r" || $_ eq "\n" || $_ eq "\r\n")'.
Why are the line endings in the file not consistent with what your Perl implementation expects? If you are building with Cygwin Perl in Unix line-ending mode on Windows then you should check out with Cygwin SVN in Unix line-ending mode and this will work just fine. This is the approach that the instructions for building on Windows take.
This file was replaced with python code: https://github.com/WebKit/WebKit/commit/ca8aedd3137dc4c62d870bc7985937fc2b380c2a Marking this as 'RESOLVED WONTFIX'.