[Cleanup] Remove some expired omnibox field trials.

ios/chrome/browser/ios_chrome_field_trials.cc

Index: ios/chrome/browser/ios_chrome_field_trials.cc
diff --git a/ios/chrome/browser/ios_chrome_field_trials.cc b/ios/chrome/browser/ios_chrome_field_trials.cc
index 7d9f19d48b792d21bc7d8ee15e620cd67a632dc1..088781569948139583fb0561e5b7af4d32af1c1e 100644
--- a/ios/chrome/browser/ios_chrome_field_trials.cc
+++ b/ios/chrome/browser/ios_chrome_field_trials.cc
@@ -5,23 +5,9 @@
 #include "ios/chrome/browser/ios_chrome_field_trials.h"
 
 #include "base/metrics/field_trial.h"
-#include "components/omnibox/browser/omnibox_field_trial.h"
-
-namespace {
-
-// Instantiates dynamic field trials by querying their state to ensure they
-// get reported as used.
-void InstantiateDynamicTrials() {
-  // Activate the autocomplete dynamic field trials.
-  OmniboxFieldTrial::ActivateDynamicTrials();
-
-  // Activate the iOS tab eviction dynamic field trials.
-  base::FieldTrialList::FindValue("TabEviction");
-}
-
-}  // namespace
 
 void SetupFieldTrials(const base::CommandLine& command_line,
                       const base::Time& install_time) {
-  InstantiateDynamicTrials();
+  // Activate the iOS tab eviction dynamic field trials.
+  base::FieldTrialList::FindValue("TabEviction");
 }