Update the toolbar coverage test to use the a layout toolbar declarat…

…ion present in default layout. Remove the previews correction made because it's not solve the problem where is checking if the toolbar HTML is not empty.

dev/tests/integration/testsuite/Magento/Catalog/Block/Product/ListTest.php

@@ -55,16 +55,16 @@ public function testToolbarCoverage()
         $parent = $this->_getLayout()->createBlock(\Magento\Catalog\Block\Product\ListProduct::class, 'parent');
 
         /* Prepare toolbar block */
+        $this->_getLayout()->createBlock(\Magento\Catalog\Block\Product\ProductList\Toolbar::class, 'product_list_toolbar');
+        $parent->setToolbarBlockName('product_list_toolbar');
+
         $toolbar = $parent->getToolbarBlock();
         $this->assertInstanceOf(\Magento\Catalog\Block\Product\ProductList\Toolbar::class, $toolbar, 'Default Toolbar');
 
         $parent->setChild('toolbar', $toolbar);
         /* In order to initialize toolbar collection block toHtml should be called before toolbar toHtml */
         $this->assertEmpty($parent->toHtml(), 'Block HTML'); /* Template not specified */
         $this->assertEquals('grid', $parent->getMode(), 'Default Mode'); /* default mode */
-
-        /* In order to use toolbar html you need a collection to be set to toolbar block */
-        $parent->getToolbarBlock()->setCollection($parent->getLoadedProductCollection());
         $this->assertNotEmpty($parent->getToolbarHtml(), 'Toolbar HTML'); /* toolbar for one simple product */
     }