Revert "[MemSheriff] Disable failing tests."

This reverts commit 6cff678a.

The tests should have been fixed with these CLs:
https://codereview.chromium.org/310493002/
https://codereview.chromium.org/302153003/

BUG=chromium:379140
NOTRY=true
Signed-off-by: Simon Que <sque@chromium.org>

Review URL: https://codereview.chromium.org/304153017

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@274482 0039d316-1c4b-4281-b951-d872f2087c98

tools/valgrind/gtest_exclude/unit_tests.gtest-memcheck.txt

@@ -13,7 +13,3 @@ ExtensionUpdaterTest.TestMultipleManifestDownloading
 
 # Test fail: crbug.com/314216
 ExtensionIconManagerTest.LoadComponentExtensionResource
-
-# fail due to incorrect login state (crbug.com/379140)
-LoginStateNotificationBlockerChromeOSTest.BaseTest
-LoginStateNotificationBlockerChromeOSTest.AlwaysAllowedNotifier