Breakpad DWARF parser: Expand comments for ByteReader class.
Breakpad DWARF parser: Expand comments for ByteReader class.

This is preparation for adding support for reading Linux C++ exception
handling data's encoded pointers. The change should have no user-visible
effect; it simply expands the comments for dwarf2reader::ByteReader, and
regroups the member functions.

a=jimblandy, r=nealsid


git-svn-id: 7939527bf0a06ad24ad020f729d5600cb42ed5d7@522 4c0a9323-5329-0410-9bdc-e9ce6186880e

mikewied/breakpad,mikewied/breakpad,mikewied/breakpad,mikewied/breakpad,mikewied/breakpad,mikewied/breakpad