Remove migrateNetworkPredictionPreferences().

migrateNetworkPredictionPreferences has been part of
PrivacyPreferencesManager ever since it was upstreamed
on 2015-02-19 at https://codereview.chromium.org/935903002.
This removal only affects users who had set this particular
preference to non-default before 2015 and have not launched
their Chrome since than.

Remove now unused PRIVACY_NETWORK_PREDICTIONS.

Bug: 526773
Change-Id: Iba72578c9e7bd77e95433098b29d727166326d97
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2568665Reviewed-by: Marc Treib <treib@chromium.org>
Reviewed-by: Natalie Chouinard <chouinard@chromium.org>
Reviewed-by: Ilya Sherman <isherman@chromium.org>
Commit-Queue: Bence Béky <bnc@chromium.org>
Cr-Commit-Position: refs/heads/master@{#836075}

chrome/android/java/src/org/chromium/chrome/browser/privacy/settings/PrivacyPreferencesManagerImpl.java

@@ -45,91 +45,6 @@ public class PrivacyPreferencesManagerImpl implements PrivacyPreferencesManager
         return sInstance;
     }
 
-    @Override
-    public void migrateNetworkPredictionPreferences() {
-        // See if PREF_NETWORK_PREDICTIONS is an old boolean value.
-        boolean predictionOptionIsBoolean = false;
-        try {
-            mPrefs.readString(ChromePreferenceKeys.PRIVACY_NETWORK_PREDICTIONS, "");
-        } catch (ClassCastException ex) {
-            predictionOptionIsBoolean = true;
-        }
-
-        // Nothing to do if the user or this migration code has already set the new
-        // preference.
-        if (!predictionOptionIsBoolean && obsoleteNetworkPredictionOptionsHasUserSetting()) {
-            return;
-        }
-
-        // Nothing to do if the old preferences are unset.
-        if (!predictionOptionIsBoolean
-                && !mPrefs.contains(ChromePreferenceKeys.PRIVACY_BANDWIDTH_OLD)
-                && !mPrefs.contains(ChromePreferenceKeys.PRIVACY_BANDWIDTH_NO_CELLULAR_OLD)) {
-            return;
-        }
-
-        // Migrate if the old preferences are at their default values.
-        // (Note that for PREF_BANDWIDTH*, if the setting is default, then there is no way to tell
-        // whether the user has set it.)
-        final String prefBandwidthDefault =
-                BandwidthType.title(BandwidthType.Type.PRERENDER_ON_WIFI);
-        final String prefBandwidth =
-                mPrefs.readString(ChromePreferenceKeys.PRIVACY_BANDWIDTH_OLD, prefBandwidthDefault);
-        boolean prefBandwidthNoCellularDefault = true;
-        boolean prefBandwidthNoCellular =
-                mPrefs.readBoolean(ChromePreferenceKeys.PRIVACY_BANDWIDTH_NO_CELLULAR_OLD,
-                        prefBandwidthNoCellularDefault);
-
-        if (!(prefBandwidthDefault.equals(prefBandwidth))
-                || (prefBandwidthNoCellular != prefBandwidthNoCellularDefault)) {
-            boolean newValue = true;
-            // Observe PREF_BANDWIDTH on mobile network capable devices.
-            if (isMobileNetworkCapable()) {
-                if (mPrefs.contains(ChromePreferenceKeys.PRIVACY_BANDWIDTH_OLD)) {
-                    @BandwidthType.Type
-                    int prefetchBandwidthTypePref =
-                            BandwidthType.getBandwidthFromTitle(prefBandwidth);
-                    if (BandwidthType.Type.NEVER_PRERENDER == prefetchBandwidthTypePref) {
-                        newValue = false;
-                    } else if (BandwidthType.Type.PRERENDER_ON_WIFI == prefetchBandwidthTypePref
-                            || BandwidthType.Type.ALWAYS_PRERENDER == prefetchBandwidthTypePref) {
-                        newValue = true;
-                    }
-                }
-            }
-            // Observe PREF_BANDWIDTH_NO_CELLULAR on devices without mobile network.
-            else {
-                if (mPrefs.contains(ChromePreferenceKeys.PRIVACY_BANDWIDTH_NO_CELLULAR_OLD)) {
-                    newValue = prefBandwidthNoCellular;
-                }
-            }
-            // Save new value in Chrome PrefService.
-            setNetworkPredictionEnabled(newValue);
-        }
-
-        // Delete old sharedPreferences.
-
-        // Delete PREF_BANDWIDTH and PREF_BANDWIDTH_NO_CELLULAR: just migrated these options.
-        if (mPrefs.contains(ChromePreferenceKeys.PRIVACY_BANDWIDTH_OLD)) {
-            mPrefs.removeKey(ChromePreferenceKeys.PRIVACY_BANDWIDTH_OLD);
-        }
-        if (mPrefs.contains(ChromePreferenceKeys.PRIVACY_BANDWIDTH_NO_CELLULAR_OLD)) {
-            mPrefs.removeKey(ChromePreferenceKeys.PRIVACY_BANDWIDTH_NO_CELLULAR_OLD);
-        }
-        // Also delete ALLOW_PRERENDER, which was updated based on PREF_BANDWIDTH[_NO_CELLULAR] and
-        // network connectivity type, therefore does not carry additional information.
-        if (mPrefs.contains(ChromePreferenceKeys.PRIVACY_ALLOW_PRERENDER_OLD)) {
-            mPrefs.removeKey(ChromePreferenceKeys.PRIVACY_ALLOW_PRERENDER_OLD);
-        }
-        // Delete bool PREF_NETWORK_PREDICTIONS so that string values can be stored. Note that this
-        // SharedPreference carries no information, because it used to be overwritten by
-        // kNetworkPredictionEnabled on startup, and now it is overwritten by
-        // kNetworkPredictionOptions on startup.
-        if (mPrefs.contains(ChromePreferenceKeys.PRIVACY_NETWORK_PREDICTIONS)) {
-            mPrefs.removeKey(ChromePreferenceKeys.PRIVACY_NETWORK_PREDICTIONS);
-        }
-    }
-
     protected boolean isNetworkAvailable() {
         ConnectivityManager connectivityManager =
                 (ConnectivityManager) mContext.getSystemService(Context.CONNECTIVITY_SERVICE);
@@ -152,7 +67,6 @@ public class PrivacyPreferencesManagerImpl implements PrivacyPreferencesManager
     @Override
     public boolean shouldPrerender() {
         if (!DeviceClassManager.enablePrerendering()) return false;
-        migrateNetworkPredictionPreferences();
         return canPrefetchAndPrerender();
     }
 

chrome/android/java/src/org/chromium/chrome/browser/privacy/settings/PrivacySettings.java

@@ -63,7 +63,6 @@ public class PrivacySettings
     public void onCreatePreferences(Bundle savedInstanceState, String rootKey) {
         PrivacyPreferencesManagerImpl privacyPrefManager =
                 PrivacyPreferencesManagerImpl.getInstance();
-        privacyPrefManager.migrateNetworkPredictionPreferences();
         SettingsUtils.addPreferencesFromResource(this, R.xml.privacy_preferences);
         assert NEW_PRIVACY_PREFERENCE_ORDER.length
                 == getPreferenceScreen().getPreferenceCount()

chrome/android/java/src/org/chromium/chrome/browser/sync/settings/GoogleServicesSettings.java

@@ -98,8 +98,6 @@ public class GoogleServicesSettings
 
     @Override
     public void onCreatePreferences(@Nullable Bundle savedInstanceState, String rootKey) {
-        mPrivacyPrefManager.migrateNetworkPredictionPreferences();
-
         getActivity().setTitle(R.string.prefs_google_services);
         setHasOptionsMenu(true);
 

chrome/android/java/src/org/chromium/chrome/browser/sync/settings/SyncAndServicesSettings.java

@@ -173,8 +173,6 @@ public class SyncAndServicesSettings extends PreferenceFragmentCompat
         mIsFromSigninScreen =
                 IntentUtils.safeGetBoolean(getArguments(), IS_FROM_SIGNIN_SCREEN, false);
 
-        mPrivacyPrefManager.migrateNetworkPredictionPreferences();
-
         getActivity().setTitle(R.string.prefs_sync_and_services);
         setHasOptionsMenu(true);
         if (mIsFromSigninScreen) {

chrome/browser/preferences/android/java/src/org/chromium/chrome/browser/preferences/ChromePreferenceKeys.java

@@ -545,7 +545,6 @@ public final class ChromePreferenceKeys {
 
     public static final String PRIVACY_METRICS_REPORTING = "metrics_reporting";
     public static final String PRIVACY_METRICS_IN_SAMPLE = "in_metrics_sample";
-    public static final String PRIVACY_NETWORK_PREDICTIONS = "network_predictions";
     public static final String PRIVACY_BANDWIDTH_OLD = "prefetch_bandwidth";
     public static final String PRIVACY_BANDWIDTH_NO_CELLULAR_OLD = "prefetch_bandwidth_no_cellular";
     public static final String PRIVACY_ALLOW_PRERENDER_OLD = "allow_prefetch";

chrome/browser/preferences/android/java/src/org/chromium/chrome/browser/preferences/GrandfatheredChromePreferenceKeys.java

@@ -133,7 +133,6 @@ public class GrandfatheredChromePreferenceKeys {
                 ChromePreferenceKeys.PRIVACY_BANDWIDTH_OLD,
                 ChromePreferenceKeys.PRIVACY_METRICS_IN_SAMPLE,
                 ChromePreferenceKeys.PRIVACY_METRICS_REPORTING,
-                ChromePreferenceKeys.PRIVACY_NETWORK_PREDICTIONS,
                 ChromePreferenceKeys.PROFILES_BOOT_TIMESTAMP,
                 ChromePreferenceKeys.PROMOS_SKIPPED_ON_FIRST_START,
                 ChromePreferenceKeys.REACHED_CODE_PROFILER_GROUP,

chrome/browser/privacy/settings/java/src/org/chromium/chrome/browser/privacy/settings/PrivacyPreferencesManager.java

@@ -10,13 +10,6 @@ import org.chromium.components.minidump_uploader.util.CrashReportingPermissionMa
  * Manages preferences related to privacy, metrics reporting, prerendering, and network prediction.
  */
 public interface PrivacyPreferencesManager extends CrashReportingPermissionManager {
-    /**
-     * Migrate and delete old preferences.  Note that migration has to happen in Android-specific
-     * code because we need to access ALLOW_PRERENDER sharedPreference.
-     * TODO(crbug.com/526773): remove this migration code.
-     */
-    void migrateNetworkPredictionPreferences();
-
     /**
      * Checks whether prerender should be allowed and updates the preference if it is not set yet.
      * @return Whether prerendering should be allowed.