[ios] Do not show location permissions prompt if in experiment group

Bug: 1138603
Change-Id: I97b13948b8859074d6288ae2af5b0cf791a3e627
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2521341
Commit-Queue: Chris Lu <thegreenfrog@chromium.org>
Commit-Queue: Rohit Rao <rohitrao@chromium.org>
Reviewed-by: Rohit Rao <rohitrao@chromium.org>
Auto-Submit: Chris Lu <thegreenfrog@chromium.org>
Cr-Commit-Position: refs/heads/master@{#825619}

ios/chrome/browser/ui/main/scene_controller.mm

@@ -905,10 +905,12 @@ const char kMultiWindowOpenInNewWindowHistogram[] =
                 name:kChromeFirstRunUIDidFinishNotification
               object:nil];
 
-  // As soon as First Run has finished, give OmniboxGeolocationController an
-  // opportunity to present the iOS system location alert.
-  [[OmniboxGeolocationController sharedInstance]
-      triggerSystemPromptForNewUser:YES];
+  if (!location_permissions_field_trial::IsInRemoveFirstRunPromptGroup()) {
+    // As soon as First Run has finished, give OmniboxGeolocationController an
+    // opportunity to present the iOS system location alert.
+    [[OmniboxGeolocationController sharedInstance]
+        triggerSystemPromptForNewUser:YES];
+  }
 }
 
 // Presents the sign-in upgrade promo if is relevant and possible.