[DevTools] Remove Object.values and Object.isEmpty from utilities.js
- replaced some object-based maps with real Map;
- remove Object.values and Object.isEmpty from utilities.js;
- better typing;
Object.values method will be added in ES2017. Closure compiler already supports it via externs, to roll it we need to remove it. It was mostly used for Objects that were used for maps, it's better to have real maps instead.
R=dgozman@chromium.org,lushnikov@chromium.org
Committed:
https://crrev.com/178c750299b0c864c76bbe64e6830144d02816ea
Cr-Commit-Position: refs/heads/master@{#406634}