Revert "[unified-consent] Refactor migration code and add settings updates"

This reverts commit 28ac1ad7.

Reason for revert: Looks like this broke components_unittests on iOS:
https://ci.chromium.org/p/chromium/builders/luci.chromium.ci/ios-simulator/36547

Original change's description:
> [unified-consent] Refactor migration code and add settings updates
> 
> The migration code in the UnifiedConsentService is refactored:
>  - The migration state IN_PROGRESS_SHOULD_SHOW_CONSENT_BUMP is
>  extracted to it's own pref kShouldShowUnifiedConsentBump.
>  - The migration state kInProgressWaitForSyncInit is introduced
>  to be able to update the settings for migration when sync is
>  initialized.
> 
> Additional changes:
>  - ShouldShowConsentBump only returns true if the consent bump
>  feature is enabled.
>  - The rollback enables sync-everything now also when the user is
>  not syncing USER_EVENTS (which is disabled during the migration).
> 
> Users that previously had the unified consent feature enabled and
> for which ShouldShowConsentBump=true, will not be shown the consent
> bump anymore after this CL is landed. This will only affect a few
> users on Canary and Dev.
> 
> Bug: 863932
> Change-Id: I211805f9059cd26056ed81d01ff19470b8caed3c
> Reviewed-on: https://chromium-review.googlesource.com/1172690
> Reviewed-by: David Roger <droger@chromium.org>
> Reviewed-by: Elly Fong-Jones <ellyjones@chromium.org>
> Commit-Queue: Thomas Tangl <tangltom@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#584341}

TBR=ellyjones@chromium.org,droger@chromium.org,tangltom@chromium.org

Change-Id: Ic50e5f7e4ac7d04be1c170b3811fd594980c71c3
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Bug: 863932
Reviewed-on: https://chromium-review.googlesource.com/1180682Reviewed-by: Nico Weber <thakis@chromium.org>
Commit-Queue: Nico Weber <thakis@chromium.org>
Cr-Commit-Position: refs/heads/master@{#584350}

chrome/browser/ui/webui/signin/login_ui_service.cc

@@ -116,7 +116,8 @@ class ConsentBumpActivator : public BrowserListObserver,
     unified_consent::UnifiedConsentService* consent_service =
         UnifiedConsentServiceFactory::GetForProfile(profile_);
 
-    consent_service->MarkConsentBumpShown();
+    consent_service->MarkMigrationComplete(
+        unified_consent::ConsentBumpSuppressReason::kNone);
 
     switch (result) {
       case LoginUIService::CONFIGURE_SYNC_FIRST:

components/unified_consent/pref_names.cc

@@ -7,11 +7,6 @@
 namespace unified_consent {
 namespace prefs {
 
-// Boolean indicating whether all criteria is met for the consent bump to be
-// shown.
-const char kShouldShowUnifiedConsentBump[] =
-    "unified_consent.consent_bump.should_show";
-
 // Boolean that is true when the user opted into unified consent.
 const char kUnifiedConsentGiven[] = "unified_consent_given";
 

components/unified_consent/pref_names.h

@@ -8,7 +8,6 @@
 namespace unified_consent {
 namespace prefs {
 
-extern const char kShouldShowUnifiedConsentBump[];
 extern const char kUnifiedConsentGiven[];
 extern const char kUnifiedConsentMigrationState[];
 extern const char kUrlKeyedAnonymizedDataCollectionEnabled[];

components/unified_consent/unified_consent_service.h

@@ -31,10 +31,10 @@ using Service = UnifiedConsentServiceClient::Service;
 using ServiceState = UnifiedConsentServiceClient::ServiceState;
 
 enum class MigrationState : int {
-  kNotInitialized = 0,
-  kInProgressWaitForSyncInit = 1,
-  // Reserve space for other kInProgress* entries to be added here.
-  kCompleted = 10,
+  NOT_INITIALIZED = 0,
+  IN_PROGRESS_SHOULD_SHOW_CONSENT_BUMP = 1,
+  // Reserve space for other IN_PROGRESS_* entries to be added here.
+  COMPLETED = 10,
 };
 
 enum class ConsentBumpSuppressReason {
@@ -75,14 +75,19 @@ class UnifiedConsentService : public KeyedService,
   void SetUnifiedConsentGiven(bool unified_consent_given);
   bool IsUnifiedConsentGiven();
 
-  // Returns true if all criteria is met to show the consent bump.
+  // Helper function for the consent bump. The consent bump has to
+  // be shown depending on the migration state.
+  MigrationState GetMigrationState();
+  // Returns true if the consent bump needs to be shown to the user as part
+  // of the migration of the Chrome profile to unified consent.
   bool ShouldShowConsentBump();
-  // Marks the consent bump as shown. Any future calls to
-  // |ShouldShowConsentBump| are guaranteed to return false.
-  void MarkConsentBumpShown();
-  // Records the consent bump suppress reason and updates the state whether the
-  // consent bump should be shown. Note: In some cases, e.g. sync paused,
-  // |ShouldShowConsentBump| will still return true.
+  // Finishes the migration to unified consent. All future calls to
+  // |GetMigrationState| are guranteed to return |MIGRATION_COMPLETED|.
+  // Takes as argument the suppress reason for not showing the consent
+  // bump if it wasn't shown.
+  void MarkMigrationComplete(ConsentBumpSuppressReason suppress_reason);
+  // Records the suppress reason for the consent bump without changing the
+  // migration state.
   void RecordConsentBumpSuppressReason(
       ConsentBumpSuppressReason suppress_reason);
 
@@ -110,17 +115,9 @@ class UnifiedConsentService : public KeyedService,
   // Enables/disables syncing everything if the sync engine is initialized.
   void SetSyncEverythingIfPossible(bool sync_everything);
 
-  // Migration helpers.
-  MigrationState GetMigrationState();
-  void SetMigrationState(MigrationState migration_state);
-  // Called when the unified consent service is created. This sets the
-  // |kShouldShowUnifiedConsentBump| pref to true if the user is eligible and
-  // calls |UpdateSettingsForMigration| at the end.
+  // Called when the unified consent service is created to resolve
+  // inconsistencies with sync-related prefs.
   void MigrateProfileToUnifiedConsent();
-  // Updates the settings preferences for the migration when the sync engine is
-  // initialized. When it is not, this function will be called again from
-  // |OnStateChanged| when the sync engine is initialized.
-  void UpdateSettingsForMigration();
 
   // Returns true if all non-personalized services are enabled.
   bool AreAllNonPersonalizedServicesEnabled();
@@ -128,10 +125,6 @@ class UnifiedConsentService : public KeyedService,
   // Checks if all on-by-default non-personalized services are on.
   bool AreAllOnByDefaultPrivacySettingsOn();
 
-  // Helper that checks whether it's okay to call
-  // |SyncService::OnUserChoseDatatypes|.
-  bool IsSyncConfigurable();
-
   std::unique_ptr<UnifiedConsentServiceClient> service_client_;
   PrefService* pref_service_;
   identity::IdentityManager* identity_manager_;