Squashed commit of the following:

commit 35ade1c72b5fe34c177712108ccbc070eab11a87
Author: Shimeng (Simon) Wang <swang@google.com>
Date:   Thu Mar 4 16:29:01 2010 -0800

    Alternative way to fix the history picture drawing issue.

    Disable zoom part for history picture mode.

    Bug: 2462039

commit 1a27acaa36c60546e5e6b2e1caf4ce5488dad14b
Author: Shimeng (Simon) Wang <swang@google.com>
Date:   Thu Mar 4 16:06:41 2010 -0800

    Use the screen width to derive the desired scale.

    This is to fix the history picture draw issue.  Since the mActualScale
    will be changed in some other places.

    Bug: 2462039