Revert of WebUI: Disable all JS tests in MSAN, ASAN, and TSAN bots.

chrome/test/data/webui/md_history/md_history_browsertest.js

Index: chrome/test/data/webui/md_history/md_history_browsertest.js
diff --git a/chrome/test/data/webui/md_history/md_history_browsertest.js b/chrome/test/data/webui/md_history/md_history_browsertest.js
index ebcb6ab538f42eb06ade22334e88702e77393b67..22d988a1b02ee6bd0f34470dc23e08812aea1eee 100644
--- a/chrome/test/data/webui/md_history/md_history_browsertest.js
+++ b/chrome/test/data/webui/md_history/md_history_browsertest.js
@@ -107,9 +107,10 @@
   ]),
 };
 
-// Times out on debug builders because the History page can take several seconds
-// to load in a Debug build. See https://crbug.com/669227.
-GEN('#if !defined(NDEBUG)');
+// Times out on debug builders and may time out on memory bots because
+// the History page can take several seconds to load in a Debug build. See
+// https://crbug.com/669227.
+GEN('#if defined(MEMORY_SANITIZER) || !defined(NDEBUG)');
 GEN('#define MAYBE_All DISABLED_All');
 GEN('#else');
 GEN('#define MAYBE_All All');