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* Changes received from browser are multiplexed and passed on to each observer.
* Each observer extracts the required subset of observations from bulk observations of the connnection using its array of indices.
* The callback is fired with a map of object store to array of observations.

Current Implementation and Future Scope: http://goo.gl/r0eUpe

Reference: https://github.com/dmurph/indexed-db-observers/blob/gh-pages/EXPLAINER.md

BUG=609934

Review-Url: https://codereview.chromium.org/2125213002
Cr-Commit-Position: refs/heads/master@{#406722}