[ios] Turn off Client-side Trending Queries experiment

Also checks FeatureList::IsFeatureOverridden for commandline and
chrome://flags overrides since that is the correct way.

(cherry picked from commit b9018ed)

Bug: 1359488
Change-Id: I968bfe1a7560af4cc8e19a29130ad3dfd5aaffad
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/4134229
Reviewed-by: Sergio Collazos <sczs@chromium.org>
Commit-Queue: Sergio Collazos <sczs@chromium.org>
Auto-Submit: Chris Lu <thegreenfrog@chromium.org>
Cr-Original-Commit-Position: refs/heads/main@{#1088793}
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/4139903
Cr-Commit-Position: refs/branch-heads/5481@{#151}
Cr-Branched-From: 130f3e4-refs/heads/main@{#1084008}

ios/chrome/browser/flags/ios_chrome_field_trials.mm

@@ -11,7 +11,6 @@
 #import "ios/chrome/browser/application_context/application_context.h"
 #import "ios/chrome/browser/paths/paths.h"
 #import "ios/chrome/browser/ui/first_run/fre_field_trial.h"
-#import "ios/chrome/browser/ui/first_run/trending_queries_field_trial.h"
 #import "ios/chrome/browser/ui/ntp/ios_popular_sites_field_trial.h"
 
 #if !defined(__has_feature) || !__has_feature(objc_arc)
@@ -41,9 +40,6 @@
   // See http://crrev/c/1128269 for an example.
   fre_field_trial::Create(entropy_providers.low_entropy(), feature_list,
                           GetApplicationContext()->GetLocalState());
-  trending_queries_field_trial::Create(
-      entropy_providers.low_entropy(), feature_list,
-      GetApplicationContext()->GetLocalState());
   ios_popular_sites_field_trial::Create(
       entropy_providers.low_entropy(), feature_list,
       GetApplicationContext()->GetLocalState());

ios/chrome/browser/ui/first_run/trending_queries_field_trial.cc

@@ -186,10 +186,9 @@ void Create(const base::FieldTrial::EntropyProvider& low_entropy_provider,
   // Don't create the trial if either feature is enabled in chrome://flags. This
   // condition is to avoid having multiple registered trials overriding the same
   // feature.
-  if (base::FieldTrialList::TrialExists(
-          kContentSuggestionsUIModuleRefreshFlagOverrideFieldTrialName) ||
-      base::FieldTrialList::TrialExists(
-          kTrendingQueriesFlagOverrideFieldTrialName)) {
+  if (feature_list->IsFeatureOverridden(
+          kContentSuggestionsUIModuleRefreshNewUser.name) ||
+      feature_list->IsFeatureOverridden(kTrendingQueriesModuleNewUser.name)) {
     return;
   }