track our own chromium_org

Change-Id: I7508864d817fc3e9245e18799e45830b2856dc16
update readme

Change-Id: I9ac619b191787e93d6e67353e1621c9d6a11d228
Merge branch 'kk4.4' of https://github.com/SlimRoms/platform_manifest into kk4.4