[MemSheriff] disable failing test

BUG=587664
TBR=tbansai@chromium.org, thestig@chromium.org, reillyg@chromium.org
NOTRY=true

Review URL: https://codereview.chromium.org/1708043002

Cr-Commit-Position: refs/heads/master@{#376047}

tools/valgrind/gtest_exclude/components_unittests.gtest.txt

@@ -6,3 +6,6 @@ AudioDirectiveListTest.*
 
 # http://crbug.com/523462
 PluginsFieldTrialTest.NoPrefLeftBehind
+
+# Fails under valgrind Linux, see http://crbug.com/587664
+DataReductionProxyConfigServiceClientTest.HTTPRequests