Since signer is now optional, it makes more sense to pass it in setter
function.
Also fix a problem in command line that if a signer or key source is
not specified correctly, the program should return immediately.
Change-Id: I3be6a4e2ba7bf7b8d5589ac8268390a0fe08a626
This is a follow up to previous CL.
Generated using command:
find {media,app,mpd} -type f -exec sed -r -i 's/#include "(.*)"/#include
"packager\/\1"/' {} \;
common.gypi and mpd.gyp are also modified to take the path change into
consideration.
Change-Id: I1fb102b4eb73ae5fde5f4ab303a12cec09b05c33