Fix text rendering [DO NOT MERGE]

There are still some errors
1. Little vertical clippping for extra tall glyphs.
2. Breaking into scripts isn't perfect which results in incorrect layout
of text.

Change-Id: I54de3c05eca5e8affb1135c120eea24c3afe8a47
(cherry picked from commit 92a169fa2e1bab7d93089196c33c2de12f9eae82)