MDVA-222: Port down MAGETWO-50611

Author: isitnikov

app/code/Magento/Config/Model/Config/Backend/Cache.php

@@ -22,12 +22,14 @@ class Cache extends \Magento\Framework\App\Config\Value
     /**
      * Clean cache, value was changed
      *
-     * @return void
+     * @return $this
      */
     public function afterSave()
     {
         if ($this->isValueChanged()) {
             $this->_cacheManager->clean($this->_cacheTags);
         }
+
+        return $this;
     }
 }

app/code/Magento/Config/Model/Config/Backend/Datashare.php

@@ -14,9 +14,10 @@
 class Datashare extends \Magento\Framework\App\Config\Value
 {
     /**
-     * @return void
+     * @return $this
      */
     public function afterSave()
     {
+        return $this;
     }
 }

app/code/Magento/Tax/Model/Config/Price/IncludePrice.php

@@ -8,11 +8,13 @@
 class IncludePrice extends \Magento\Framework\App\Config\Value
 {
     /**
-     * @return void
+     * @return $this
      */
     public function afterSave()
     {
-        parent::afterSave();
+        $result = parent::afterSave();
         $this->_cacheManager->clean(['checkout_quote']);
+
+        return $result;
     }
 }

app/code/Magento/WebapiSecurity/Model/Plugin/CacheInvalidator.php

@@ -26,17 +26,20 @@ public function __construct(\Magento\Framework\App\Cache\TypeListInterface $cach
      * Invalidate WebApi cache if needed.
      * 
      * @param \Magento\Framework\App\Config\Value $subject
+     * @param \Magento\Framework\App\Config\Value $result
      * @return \Magento\Framework\App\Config\Value
      * @SuppressWarnings(PHPMD.UnusedFormalParameter)
      */
-    public function afterAfterSave(\Magento\Framework\App\Config\Value $subject)
-    {
+    public function afterAfterSave(
+        \Magento\Framework\App\Config\Value $subject,
+        \Magento\Framework\App\Config\Value $result
+    ) {
         if ($subject->getPath() == \Magento\WebapiSecurity\Model\Plugin\AnonymousResourceSecurity::XML_ALLOW_INSECURE
             && $subject->isValueChanged()
         ) {
             $this->cacheTypeList->invalidate(\Magento\Framework\App\Cache\Type\Webapi::TYPE_IDENTIFIER);
         }
 
-        return $subject;
+        return $result;
     }
 }