Repair WebRtcBrowserTest names in drmemory exclusions file

Repair WebRtcBrowserTest names in drmemory exclusions file
(these tests changed names when they went from TEST_P to
 TEST_F in r283700).

Fix spelling error in three test names.

Eliminate memory error suppressions that were put in as fixes:
* Revert "[MemSheriff] Suppress unreadable mem access"
* This reverts commit a922608663a6fd861aeff6fd2bc3984dcbda86db.
* (aka svn r283943)

* Revert "[MemSheriff] Disable failing tests"
* This reverts commit 565a8552b8e194807358b33ff741ae55ac9da901.
* (aka svn r284133)

BUG=394957, 395172, 389132, 389098
Committed: https://src.chromium.org/viewvc/chrome?view=rev&revision=284308

[ncarter (slow), 2014-07-18 22:26:25]

vrk -- please review

[ncarter (slow), 2014-07-18 22:29:18]

+groby fyi

[vrk (LEFT CHROMIUM), 2014-07-18 22:30:03]

lgtm media

[ncarter (slow), 2014-07-18 22:33:28]

The CQ bit was checked by nick@chromium.org

[commit-bot: I haz the power, 2014-07-18 22:37:52]

CQ is trying da patch. Follow status at
 https://chromium-status.appspot.com/cq/nick@chromium.org/401073002/40001

[groby-ooo-7-16, 2014-07-18 22:55:11]

LGTM

[commit-bot: I haz the power, 2014-07-19 02:08:02]

FYI, CQ is re-trying this CL (attempt #1).
The failing builders are:
  android_dbg_triggered_tests on tryserver.chromium
(http://build.chromium.org/p/tryserver.chromium/builders/android_dbg_triggered...)

[commit-bot: I haz the power, 2014-07-19 04:43:17]

Change committed as 284308