linux.chromeos.valgrind -= browser_tests_br
linux.chromeos.valgrind -= browser_tests_br

This patch excludes the BuildRunner version of 'browser_tests' in addition to
the already-excluded 'browser_tests'.

BUG=374252
TEST=localtest
R=stip@chromium.org

Review URL: https://codereview.chromium.org/289173002

git-svn-id: 239fca9b83025a0b6f823aeeca02ba5be3d9fd76@271369 0039d316-1c4b-4281-b951-d872f2087c98

eunchong/build,eunchong/build,eunchong/build,eunchong/build