Eliminate redundancy and/or simplify default case for compiling unittest_data.h

[GoogleCodeExporter]

internal/unittest_data.h seems to use a mixture of escape sequences and raw 
non-ASCII text. For maximum portability and safety, it would be best for the 
source code to use all ASCII characters and escape the non-ASCII characters. 
This should help compiler compatibility, though there are no reports of 
breakage since this Chromium.org issue back in 2009:

https://code.google.com/p/chromium/issues/detail?id=20033

The change should be simple enough, and a script can be written to perform the 
transformation.

Original issue reported on code.google.com by [email protected] on 26 Aug 2014 at 3:27