DevTools: excessive dumping for jump-to-previous-position.html test

DevTools: excessive dumping for jump-to-previous-position.html test

This patch adds excessive dumping for jump-to-previous-position.html test.
The changes are expected to be reverted as the reason of failures will
be detected.

BUG=361588
Committed: https://src.chromium.org/viewvc/blink?view=rev&revision=174171

[lushnikov, 2014-05-16 12:12:45]

ptal

[vsevik, 2014-05-16 12:49:27]

lgtm

[lushnikov, 2014-05-16 12:56:17]

The CQ bit was checked by lushnikov@chromium.org

[commit-bot: I haz the power, 2014-05-16 12:56:28]

CQ is trying da patch. Follow status at
 https://chromium-status.appspot.com/cq/lushnikov@chromium.org/285373011/1

[commit-bot: I haz the power, 2014-05-16 13:37:59]

FYI, CQ is re-trying this CL (attempt #1).
Please consider checking whether the failures are real,
and report flakes to chrome-troopers@google.com.
The failing builders are:
  linux_blink_rel on tryserver.blink
(http://build.chromium.org/p/tryserver.blink/builders/linux_blink_rel/builds/7358)

[commit-bot: I haz the power, 2014-05-16 14:12:59]

Change committed as 174171

[lushnikov, 2014-05-30 08:49:29]

A revert of this CL has been created in
https://codereview.chromium.org/303383002/ by lushnikov@chromium.org.

The reason for reverting is: Looks like test is not accidentally failing any
more during last week. Reverting this debugging patch.