MAGETWO-65248: [Backport] - [Performance] Caching of swatches data in block cache - for 2.1.6

Author: lestare

app/code/Magento/Swatches/Block/Product/Renderer/Configurable.php

@@ -365,9 +365,8 @@ protected function getConfigurableOptionsIds(array $attributeData)
     }
 
     /**
-     * Return HTML code
+     * Produce and return block's html output.
      *
-     * @codeCoverageIgnore
      * @return string
      */
     protected function _toHtml()

app/code/Magento/Swatches/Block/Product/Renderer/Listing/Configurable.php

@@ -22,13 +22,29 @@ protected function getRendererTemplate()
     }
 
     /**
+     * Produce and return block's html output.
+     *
+     * @return string
+     */
+    protected function _toHtml()
+    {
+        $output = '';
+        if ($this->isProductHasSwatchAttribute) {
+            $output = parent::_toHtml();
+        }
+
+        return $output;
+    }
+
+    /**
+     * @deprecated
      * @return string
      */
     protected function getHtmlOutput()
     {
         $output = '';
         if ($this->isProductHasSwatchAttribute) {
-            $output = parent::toHtml();
+            $output = parent::getHtmlOutput();
         }
 
         return $output;