Re-enable the warm perf load test.

chrome/test/startup/feature_startup_test.cc

Index: chrome/test/startup/feature_startup_test.cc
diff --git a/chrome/test/startup/feature_startup_test.cc b/chrome/test/startup/feature_startup_test.cc
index 9056520012e72913657a9fc64a7009382a123a00..5f2ce166d960ea9d163b57831a00869568f70299 100644
--- a/chrome/test/startup/feature_startup_test.cc
+++ b/chrome/test/startup/feature_startup_test.cc
@@ -163,7 +163,7 @@ TEST_F(NewTabUIStartupTest, PerfCold) {
                  UITest::DEFAULT_THEME);
 }
 
-TEST_F(NewTabUIStartupTest, DISABLED_PerfWarm) {
+TEST_F(NewTabUIStartupTest, PerfWarm) {
   RunStartupTest("tab_warm", true /* warm */, false /* not important */,
                  UITest::DEFAULT_THEME);
 }