Remove Popular Sites experiment on iOS.

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 d1ef899ef57b8939fcf7fd27bf53cdb699d269c4..bd64bfcd88de669a3c5e5ad11bd0616b58b42cd0 100644
--- a/ios/chrome/browser/ios_chrome_field_trials.cc
+++ b/ios/chrome/browser/ios_chrome_field_trials.cc
@@ -12,8 +12,4 @@
 void SetupIOSFieldTrials() {
   // Activate the iOS tab eviction dynamic field trials.
   base::FieldTrialList::FindValue("TabEviction");
-
-  // Setup a field trial for a first run experiment on Popular sites.
-  ntp_tiles::SetUpFirstLaunchFieldTrial(GetChannel() ==
-                                        version_info::Channel::STABLE);
 }