Merge "Defer removal of activity until animation complete."

                    mStackIdToStack.valueAt(stackNdx).mExitingAppTokens;

            for (i = exitingAppTokens.size() - 1; i >= 0; i--) {

                AppWindowToken token = exitingAppTokens.get(i);

                if (!token.hasVisible && !mClosingApps.contains(token)) {

                if (!token.hasVisible && !mClosingApps.contains(token) && !token.mDeferRemoval) {

                    // Make sure there is no animation running on this token,

                    // so any windows associated with it will be removed as

                    // soon as their animations are complete