Added rotate camera button.
Added rotate camera button.

TBR=dsinclair
BUG=399

Review URL: https://codereview.appspot.com/13089046
catapult-project/catapult,catapult-project/catapult,SummerLW/Perf-Insight-Report,benschmaus/catapult,sahiljain/catapult,scottmcmaster/catapult,sahiljain/catapult,dstockwell/catapult,0x90sled/catapult,sahiljain/catapult,modulexcite/catapult,scottmcmaster/catapult,catapult-project/catapult,zeptonaut/catapult,catapult-project/catapult-csm,SummerLW/Perf-Insight-Report,benschmaus/catapult,catapult-project/catapult-csm,benschmaus/catapult,SummerLW/Perf-Insight-Report,zeptonaut/catapult,dstockwell/catapult,zeptonaut/catapult,benschmaus/catapult,catapult-project/catapult-csm,vmpstr/trace-viewer,danbeam/catapult,SummerLW/Perf-Insight-Report,SummerLW/Perf-Insight-Report,SummerLW/Perf-Insight-Report,catapult-project/catapult,catapult-project/catapult-csm,danbeam/catapult,vmpstr/trace-viewer,0x90sled/catapult,scottmcmaster/catapult,catapult-project/catapult-csm,vmpstr/trace-viewer,danbeam/catapult,sahiljain/catapult,catapult-project/catapult,modulexcite/catapult,benschmaus/catapult,catapult-project/catapult,sahiljain/catapult,benschmaus/catapult,dstockwell/catapult,sahiljain/catapult,catapult-project/catapult,modulexcite/catapult,dstockwell/catapult,catapult-project/catapult-csm,danbeam/catapult,0x90sled/catapult,catapult-project/catapult-csm,benschmaus/catapult