Remove dead feature toggle for user consents

The actual logic being toggles was removed in
https://chromium-review.googlesource.com/c/1349649 and the feature toggle
became unused even before that, so let's clean it up.

Bug: 905639
Change-Id: Iabc1d043b5d8e8a4bfcfd7586ef324a7fdae91d7
Reviewed-on: https://chromium-review.googlesource.com/c/1477836Reviewed-by: John Wu <jzw@chromium.org>
Reviewed-by: Marc Treib <treib@chromium.org>
Commit-Queue: Mikel Astiz <mastiz@chromium.org>
Auto-Submit: Mikel Astiz <mastiz@chromium.org>
Cr-Commit-Position: refs/heads/master@{#635094}

components/sync/driver/sync_driver_switches.cc

@@ -97,10 +97,6 @@ const base::Feature kSyncUserEvents{"SyncUserEvents",
 const base::Feature kSyncUserFieldTrialEvents{"SyncUserFieldTrialEvents",
                                               base::FEATURE_ENABLED_BY_DEFAULT};
 
-// Gates emission of UserConsent events.
-const base::Feature kSyncUserConsentEvents{"SyncUserConsentEvents",
-                                           base::FEATURE_ENABLED_BY_DEFAULT};
-
 // Gates registration for user language detection events.
 const base::Feature kSyncUserLanguageDetectionEvents{
     "SyncUserLanguageDetectionEvents", base::FEATURE_DISABLED_BY_DEFAULT};

components/sync/driver/sync_driver_switches.h

@@ -40,7 +40,6 @@ extern const base::Feature kSyncStandaloneTransport;
 extern const base::Feature kSyncSupportSecondaryAccount;
 extern const base::Feature kSyncUserEvents;
 extern const base::Feature kSyncUserFieldTrialEvents;
-extern const base::Feature kSyncUserConsentEvents;
 extern const base::Feature kSyncUserLanguageDetectionEvents;
 extern const base::Feature kSyncUserTranslationEvents;
 extern const base::Feature kSyncUSSBookmarks;

ios/web_view/internal/web_view_web_main_parts.mm

@@ -58,9 +58,7 @@ void WebViewWebMainParts::PreCreateThreads() {
        switches::kSyncUSSAutofillWalletData.name},
       ",");
   std::string disabled_features = base::JoinString(
-      {// TODO(crbug.com/873790): Remove after supporting user consents.
-       switches::kSyncUserConsentEvents.name,
-       // Allows form_structure.cc to run heuristics on single field forms.
+      {// Allows form_structure.cc to run heuristics on single field forms.
        // This is needed to find autofillable password forms with less than 3
        // fields in CWVAutofillControllerDelegate's
        // |autofillController:didScanForAutofillableForms:| method.