build problems, and will give better diagnostics if not.
Change-Id: I2f7a5d9b2e0c63a8189ad212125c7a5c0178c3c4
BUG=10567
TEST=
Review URL: http://codereview.chromium.org/6331007
ability to filter or manipulate content as it's passed through.
Create two example tests using this utility that cause
updates to close early to test resumes, and to add delays
to make sure the update still completes correctly.
What other tests should be created for this?
BUG=chromium-os:8207
TEST=Run by hand
Review URL: http://codereview.chromium.org/5632002
Change-Id: Iefb8c8e223fb2ba6bad2c551f7c4403a0bec6ecf