This error is one of many that shows up when setting
`compilation_mode="SIMPLE"` and is fixed in preparation:
ERROR - A Polymer() declaration cannot use 'const'.
const GrReporting = Polymer({
^
ProTip: "JSC_POLYMER_INVALID_DECLARATION" can be added to the `suppress` attribute of:
//polygerrit-ui/app:polygerrit_ui_closure_lib
Change-Id: I2f43b937bc9508270f56b81e955dfebfcd4a2ac0