Fix build with freetype2 depending on harfbuzz

Chromium uses system freetype2 by default but not harfbuzz by default,
since some newer versions of freetype2 depends on harfbuzz, we need to
configure Chromium to use system harfbuzz in those cases.

Change-Id: Ic15abe85c5b7e5ef1c3d82420efbc8605c2fe1ae
Reviewed-by: Michael Brüning <michael.bruning@theqtcompany.com>