Improve the Class documentation.

There were a few other instances of the same error reported in the bug,
plus bits that didn't make much sense, so I gave the whole file a quick
scrub.

Bug: http://code.google.com/p/android/issues/detail?id=42100
Change-Id: I40669a614c92a80038253a4adf89f8c7f7f8e95c
1 file changed