Chrome Version: 3fba7f46f286f5573abdcdd792f10e47b4e54380-refs/heads/master@{#466864}

What steps will reproduce the problem?
(1) build an polymer app following [1]
(2) open polymer web site with DevTools and put breakpoint at 
'this.page = 'view404';' line
(3) navigate to http://<polymer-app-url>/view123

[1] https://www.polymer-project.org/2.0/start/toolbox/set-up

What is the expected result?
break on breakpoint

What happens instead?
breakpoint hit and execution is instantly resumed
 

Chrome Version: 3fba7f46f286f5573abdcdd792f10e47b4e54380-refs/heads/master@{#466864}

What steps will reproduce the problem?
(1) build an polymer app following [1]
(2) open polymer web site with DevTools and put breakpoint at 
'this.page = 'view404';' line
(3) navigate to http://<polymer-app-url>/view123

[1] https://www.polymer-project.org/2.0/start/toolbox/set-up

What is the expected result?
break on breakpoint

What happens instead?
breakpoint hit and execution is instantly resumed

The issue here that polymer load new page using modern workers-related features and worker gets own set of agents and new Debugger agent gets resume call and then resume original agent break.