Extension API Modification Proposal

API Namespace: chrome.browsingData
API Owners: chrome-privacy-core@
API Overview Doc:
We would like to extend browsingData.RemovalOptions with an "origins" and an "excludeOrigins" parameter to allow extensions to selectively delete data or exclude specific origins from a deletion. 
This feature has been requested in one of the most popular extension and privacy bugs: https://crbug.com/78093

I created a short document to describe this change: 
https://docs.google.com/document/d/1WeGn1koimSgZHbmUM9bTCPMjpCqhXUSzC84VpaP2Bpk/edit

CL: https://crrev.com/c/1405012

This is based on an old and already approved proposal:
https://groups.google.com/a/chromium.org/forum/#!msg/apps-dev/-JuS6Kfff4c/peEsbyy4qA8J

Design Doc: N/A
Supplementary Resources: N/A