Replace FieldTrial::group() with Activate().

Bug: 1358242
Change-Id: If768363de609411af85deff1cca6ffe4546631f2
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/3855260
Reviewed-by: Alexei Svitkine <[email protected]>
Reviewed-by: Jared Saul <[email protected]>
Reviewed-by: Orin Jaworski <[email protected]>
Reviewed-by: Ian Barkley-Yeung <[email protected]>
Reviewed-by: Hidehiko Abe <[email protected]>
Commit-Queue: Steven Holte <[email protected]>
Cr-Commit-Position: refs/heads/main@{#1042894}
diff --git a/components/variations/variations_test_utils.cc b/components/variations/variations_test_utils.cc
index 3f3dade..0b6f941 100644
--- a/components/variations/variations_test_utils.cc
+++ b/components/variations/variations_test_utils.cc
@@ -208,7 +208,7 @@
   if (trial) {
     // Ensure the trial is registered under the correct key so we can look it
     // up.
-    trial->group();
+    trial->Activate();
   }
 
   return trial;