PrettyFormatter: Fix expand tab when syntax coloring is on.

prettify lost support for expanding tabs in r143 [1]. As a consequence,
tab width preference is no longer honored.

Gerrit now handles expanding tabs by itself in all cases, even if syntax
coloring is active.

[1] http://code.google.com/p/google-code-prettify/source/detail?r=143

Bug: issue 1872
Change-Id: I283a3620b1d130d3f66e56d3f202a5122d7a73b8
2 files changed