[Author: thomasvl]
[Author: thomasvl]

Allow the GTMLogger macros to be remapped in a prefix by checking if they
  are defined before defining them.

R=dmaclach
DELTA=5  (5 added, 0 deleted, 0 changed)

qwertme/google-toolbox-for-mac,jonreid/google-toolbox-for-mac,jonreid/google-toolbox-for-mac,qwertme/google-toolbox-for-mac,qwertme/google-toolbox-for-mac,jonreid/google-toolbox-for-mac