Remove trace of MouseEventPreconnect field trial.

chrome/browser/chrome_browser_field_trials.cc

Index: chrome/browser/chrome_browser_field_trials.cc
diff --git a/chrome/browser/chrome_browser_field_trials.cc b/chrome/browser/chrome_browser_field_trials.cc
index 1571bd85d7e524da72e2e38cfc2e3782c6cf863e..55f83b7eba6ec0e86598bc9390bcfbd0ef32ec67 100644
--- a/chrome/browser/chrome_browser_field_trials.cc
+++ b/chrome/browser/chrome_browser_field_trials.cc
@@ -47,7 +47,6 @@ void ChromeBrowserFieldTrials::InstantiateDynamicTrials() {
   // The following trials are used from renderer process.
   // Mark here so they will be sync-ed.
   base::FieldTrialList::FindValue("CLD1VsCLD2");
-  base::FieldTrialList::FindValue("MouseEventPreconnect");
   base::FieldTrialList::FindValue("DisplayList2dCanvas");
   // Activate the autocomplete dynamic field trials.
   OmniboxFieldTrial::ActivateDynamicTrials();