tree 9fea143039d131f6a591241f405815f1da5ce0a7
parent 2ceb08150512ca121acc474d94f84357f0bf0bbf
author Craig Mautner <cmautner@google.com> 1360362687 -0800
committer Craig Mautner <cmautner@google.com> 1360362687 -0800

Make ActivityStack.mHistory private.

Isolate the Activity history for later conversion to Task-based
management.

Change-Id: I4b6bf22de035c768aa705df0cc4f84486e8ede56