[chromium] Fix threaded compositor HUD crash

[chromium] Fix threaded compositor HUD crash
https://bugs.webkit.org/show_bug.cgi?id=83778

Patch by Sami Kyostila <skyostil@chromium.org> on 2012-04-12
Reviewed by James Robinson.

Don't try to read font metrics in threaded compositing mode, since we
currently can't render HUD text with the threaded compositor.

HUD is not testable in WebKit.

* platform/graphics/chromium/cc/CCHeadsUpDisplay.cpp:
(WebCore::CCHeadsUpDisplay::drawHudContents):

git-svn-id: http://svn.webkit.org/repository/webkit/trunk@114000 268f45cc-cd09-0410-ab3c-d52691b4dbfc