CPP: Fix compilation error with -DUSE_GOOGLE_BASE
CPP: Fix compilation error with -DUSE_GOOGLE_BASE

This removes the Chromium-specific (outdated) Logger interface from
default_logger.h.
The return type of set_logger_impl() differed from the one in logger.h (changed
in r430) which produced a compilation error in phonenumberutil.cc when
set_logger_impl() is used as a right value.

Logger, defined in logger.h is now used in all cases.
oneminot/libphonenumber,oneminot/libphonenumber,oneminot/libphonenumber,oneminot/libphonenumber