[MD History] Disable slow test on Debug/ASAN.

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 754d587112390b7b9160312e9dfa331add2248c2..22d988a1b02ee6bd0f34470dc23e08812aea1eee 100644
--- a/chrome/test/data/webui/md_history/md_history_browsertest.js
+++ b/chrome/test/data/webui/md_history/md_history_browsertest.js
@@ -107,7 +107,16 @@ MaterialHistoryListTest.prototype = {
   ]),
 };
 
-TEST_F('MaterialHistoryListTest', 'All', function() {
+// 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');
+GEN('#endif');
+
+TEST_F('MaterialHistoryListTest', 'MAYBE_All', function() {
   mocha.run();
 });