This indicates an attack attempt to exploit a Code Execution vulnerability in Google Chrome V8 Engine.
This issue is caused by an error in the "Object.assign" function when copying private properties. A remote attacker may be able to exploit this to execute arbitrary code within the context of the application, via a crafted web page.
Google Chrome before Version 55.0.2883.75
System Compromise: Remote attackers can gain control of vulnerable systems.
Apply the most recent upgrade or patch from the vendor.