Add advanced setting to clear WebView data

(cherry picked from commit 2b76a97989)

# Conflicts:
#	app/src/main/java/eu/kanade/tachiyomi/ui/setting/SettingsAdvancedController.kt

app/src/main/java/eu/kanade/tachiyomi/ui/setting/SettingsAdvancedController.kt

@@ -6,6 +6,8 @@ import android.content.ActivityNotFoundException
 import android.content.Intent
 import android.os.Bundle
 import android.provider.Settings
+import android.webkit.WebStorage
+import android.webkit.WebView
 import android.widget.Toast
 import androidx.appcompat.app.AlertDialog
 import androidx.core.net.toUri
@@ -49,7 +51,9 @@ import eu.kanade.tachiyomi.util.preference.titleRes
 import eu.kanade.tachiyomi.util.storage.DiskUtil
 import eu.kanade.tachiyomi.util.system.DeviceUtil
 import eu.kanade.tachiyomi.util.system.isPackageInstalled
+import eu.kanade.tachiyomi.util.system.logcat
 import eu.kanade.tachiyomi.util.system.powerManager
+import eu.kanade.tachiyomi.util.system.setDefaultSettings
 import eu.kanade.tachiyomi.util.system.toast
 import exh.debug.SettingsDebugController
 import exh.log.EHLogLevel
@@ -57,6 +61,7 @@ import exh.source.BlacklistedSources
 import exh.source.EH_SOURCE_ID
 import exh.source.EXH_SOURCE_ID
 import kotlinx.coroutines.Job
+import logcat.LogPriority
 import rikka.sui.Sui
 import uy.kohesive.injekt.Injekt
 import uy.kohesive.injekt.api.get
@@ -147,6 +152,12 @@ class SettingsAdvancedController : SettingsController() {
                 titleRes = R.string.pref_auto_clear_chapter_cache
                 defaultValue = false
             }
+            preference {
+                key = "pref_clear_webview_data"
+                titleRes = R.string.pref_clear_webview_data
+
+                onClick { clearWebViewData() }
+            }
             preference {
                 key = "pref_clear_database"
                 titleRes = R.string.pref_clear_database
@@ -486,11 +497,29 @@ class SettingsAdvancedController : SettingsController() {
                         resources?.getString(R.string.used_cache, chapterCache.readableSize)
                 }
             } catch (e: Throwable) {
+                logcat(LogPriority.ERROR, e)
                 withUIContext { activity?.toast(R.string.cache_delete_error) }
             }
         }
     }
 
+    private fun clearWebViewData() {
+        if (activity == null) return
+        try {
+            val webview = WebView(activity!!)
+            webview.setDefaultSettings()
+            webview.clearCache(true)
+            webview.clearFormData()
+            webview.clearHistory()
+            webview.clearSslPreferences()
+            WebStorage.getInstance().deleteAllData()
+            activity?.toast(R.string.webview_data_deleted)
+        } catch (e: Throwable) {
+            logcat(LogPriority.ERROR, e)
+            activity?.toast(R.string.cache_delete_error)
+        }
+    }
+
     private companion object {
         // SY -->
         private var job: Job? = null