If you scroll the model track container with your mouse wheel the panY value doesn't update to match. When panning / scanning the view jumps to the last known panY value.
If you scroll the model track container with your mouse wheel the panY value doesn't update to match. When panning / scanning the view jumps to the last known panY value.

R=dsinclair@chromium.org

Review URL: https://codereview.appspot.com/11438043
catapult-project/catapult-csm,scottmcmaster/catapult,0x90sled/catapult,zeptonaut/catapult,sahiljain/catapult,danbeam/catapult,catapult-project/catapult-csm,zeptonaut/catapult,SummerLW/Perf-Insight-Report,catapult-project/catapult,catapult-project/catapult-csm,vmpstr/trace-viewer,SummerLW/Perf-Insight-Report,dstockwell/catapult,danbeam/catapult,catapult-project/catapult,benschmaus/catapult,catapult-project/catapult,catapult-project/catapult-csm,modulexcite/catapult,dstockwell/catapult,modulexcite/catapult,danbeam/catapult,SummerLW/Perf-Insight-Report,vmpstr/trace-viewer,modulexcite/catapult,catapult-project/catapult-csm,sahiljain/catapult,scottmcmaster/catapult,benschmaus/catapult,0x90sled/catapult,danbeam/catapult,benschmaus/catapult,catapult-project/catapult,dstockwell/catapult,sahiljain/catapult,sahiljain/catapult,scottmcmaster/catapult,catapult-project/catapult-csm,benschmaus/catapult,vmpstr/trace-viewer,benschmaus/catapult,dstockwell/catapult,catapult-project/catapult-csm,benschmaus/catapult,sahiljain/catapult,zeptonaut/catapult,SummerLW/Perf-Insight-Report,catapult-project/catapult,sahiljain/catapult,catapult-project/catapult,catapult-project/catapult,SummerLW/Perf-Insight-Report,SummerLW/Perf-Insight-Report,benschmaus/catapult,0x90sled/catapult