Fix cpplint errors in inspectable_web_contents_view_linux.h
Ignore .mm files for cpplint

It doesn't process them anyway.
Fix cpplint errors in bry_application.h
Ignore cpplint errors in bry_inspectable_web_contents_view_private.h

It's not a C++ header.
Fix whitespace/comment errors
Fix cpplint errors in content_client.cc