Update cache after forcing variations

This makes the forced variation ids take effect immediately
like others after cache initialization.

Bug: 1121305
Change-Id: Id2edb803c2898b2e1f93ae3325f510b51fd0ec08
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2402168Reviewed-by: Justin Cohen <justincohen@chromium.org>
Reviewed-by: Jesse Doherty <jwd@chromium.org>
Commit-Queue: Ganggui Tang <gogerald@chromium.org>
Cr-Commit-Position: refs/heads/master@{#806339}

components/variations/variations_ids_provider.cc

@@ -108,14 +108,29 @@ VariationsIdsProvider::ForceIdsResult VariationsIdsProvider::ForceVariationIds(
                                   &default_variation_ids_set_)) {
     return ForceIdsResult::INVALID_SWITCH_ENTRY;
   }
+  if (variation_ids_cache_initialized_) {
+    // Update the cached variation ids header value after cache initialization,
+    // otherwise the change won't be in the cache.
+    base::AutoLock scoped_lock(lock_);
+    UpdateVariationIDsHeaderValue();
+  }
   return ForceIdsResult::SUCCESS;
 }
 
 bool VariationsIdsProvider::ForceDisableVariationIds(
     const std::string& command_line_variation_ids) {
   force_disabled_ids_set_.clear();
-  return ParseVariationIdsParameter(command_line_variation_ids,
-                                    &force_disabled_ids_set_);
+  if (!ParseVariationIdsParameter(command_line_variation_ids,
+                                  &force_disabled_ids_set_)) {
+    return false;
+  }
+  if (variation_ids_cache_initialized_) {
+    // Update the cached variation ids header value after cache initialization,
+    // otherwise the change won't be in the cache.
+    base::AutoLock scoped_lock(lock_);
+    UpdateVariationIDsHeaderValue();
+  }
+  return true;
 }
 
 void VariationsIdsProvider::AddObserver(Observer* observer) {

ios/chrome/browser/ui/omnibox/omnibox_egtest.mm

@@ -164,10 +164,6 @@ id<GREYMatcher> SearchCopiedTextButton() {
   }
 #endif
 
-  // TODO(crbug.com/1121305): Test is failing due to clearing the variations on
-  // first run, causing tests to fail flakily on the bots.
-  EARL_GREY_TEST_SKIPPED(@"testXClientData fails on first simulator run.");
-
   // TODO(crbug.com/1120723) This test is flakily because of a DCHECK in
   // ios/web.  Clearing browser history first works around the problem, but
   // shouldn't be necessary otherwise.  Remove once the bug is fixed.