Fix IndexedDB test to explicitly list transactions. Required by WebKit change

Fix IndexedDB test to explicitly list transactions. Required by WebKit change
in https://bugs.webkit.org/show_bug.cgi?id=70251

See thread: https://groups.google.com/a/chromium.org/group/chromium-html5/browse_thread/thread/f667458ca6455d33/1496ad2d1a67b53f#1496ad2d1a67b53f

BUG=101973
TEST=performance_ui_tests --gtest_filter='*IndexedDB*'

Committed: http://src.chromium.org/viewvc/chrome?view=rev&revision=107616

[Nico, 2011-10-27 20:40:24]

LGTM

Thanks! Maybe you can put a link to the chomium-html5 thread about this in the
CL description, but it's fine as is, too.