Fix drive check.
Fix drive check.

Missed check when moving drive from extras to ui/extras.

BUG=#999
TBR=nduca@chromium.org

Review URL: https://codereview.appspot.com/242650043.

modulexcite/catapult,scottmcmaster/catapult,0x90sled/catapult,scottmcmaster/catapult,sahiljain/catapult,catapult-project/catapult,danbeam/catapult,SummerLW/Perf-Insight-Report,catapult-project/catapult-csm,dstockwell/catapult,SummerLW/Perf-Insight-Report,catapult-project/catapult,danbeam/catapult,0x90sled/catapult,benschmaus/catapult,benschmaus/catapult,catapult-project/catapult-csm,sahiljain/catapult,benschmaus/catapult,danbeam/catapult,dstockwell/catapult,benschmaus/catapult,SummerLW/Perf-Insight-Report,zeptonaut/catapult,zeptonaut/catapult,benschmaus/catapult,sahiljain/catapult,danbeam/catapult,zeptonaut/catapult,catapult-project/catapult,catapult-project/catapult-csm,modulexcite/catapult,sahiljain/catapult,sahiljain/catapult,catapult-project/catapult-csm,SummerLW/Perf-Insight-Report,benschmaus/catapult,SummerLW/Perf-Insight-Report,catapult-project/catapult-csm,scottmcmaster/catapult,SummerLW/Perf-Insight-Report,catapult-project/catapult,catapult-project/catapult,dstockwell/catapult,sahiljain/catapult,modulexcite/catapult,0x90sled/catapult,catapult-project/catapult,catapult-project/catapult-csm,benschmaus/catapult,dstockwell/catapult,catapult-project/catapult-csm,catapult-project/catapult