mozilla-b2g/gaia — pull request #2458 by RudyLu (2012-07-16 13:28:49+00:00)
Title: Fix: to enhance virtual keyboard performance by removing border-radius &...

1. Remove border-radius & box-shadow CSS attributes.
2. Make the cache (for prefetching background images for keys) not to overlay with the main keyboard, which may introduce performance penalty.

The alternative method to enable the visuals like rounded corner is to use "multiple backgrounds" , which is not ready for now.