Use system font substitution rules for local web fonts

Change LocalFontFaceSource to use the same alternative name font
substation rules as used for system fonts.
Specifically using adjustFamilyNameToAvoidUnsupportedFonts to map
unsupported bitmap fonts to their modern true type equivalents.

BUG=376377
R=jam@chromium.org

Review URL: https://codereview.chromium.org/299703013

git-svn-id: svn://svn.chromium.org/blink/trunk@174618 bbb929c8-8fbe-4397-9dbb-9b2b20218538