[DirectWrite] Disable subpixel font positioning for certain fonts/sizes

Conditionally disable subpixel text for certain older fonts at sizes
below 16px in order to improve legibility and rendering quality. This is
limited to a specific set of fonts and does not apply to webfonts.
This list of fonts in question includes all fonts in the "Microsoft Core
fonts for the Web" collection.

Specifically the following fonts: arial, courier new, times new roman,
andale mono, comic sans, impact, georgia, trebuchet, verdana, webdings,
tahoma, and lucida console.

R=cpu@chromium.org, scottmg@chromium.org
BUG=405445,395425

Review URL: https://codereview.chromium.org/544843004

git-svn-id: svn://svn.chromium.org/blink/trunk@181492 bbb929c8-8fbe-4397-9dbb-9b2b20218538