base

Avoid multiple font cache texture uploads
Bug #8378964

This change defers drawing into layers until after the renderer for FBO0
is ready to draw. At that point, all the precaching is done which means
all glyphs can be uploaded at once in the font caches.

Change-Id: Ie1f7a7ff30f76f06fb3dbc72c7d05e66207d1ecb