MAGETWO-32624: Investigate and Annotate @api to classes and/or methods

- fixed unit test failures

Author: Joan He

app/code/Magento/Config/Model/Config/ScopeDefiner.php

@@ -39,6 +39,6 @@ public function getScope()
             'store'
         ) ? StoreScopeInterface::SCOPE_STORE : ($this->_request->getParam(
             'website'
-        ) ? StoreScopeInterface::SCOPE_WEBSITE : StoreScopeInterface::SCOPE_DEFAULT);
+        ) ? StoreScopeInterface::SCOPE_WEBSITE : ScopeConfigInterface::SCOPE_TYPE_DEFAULT);
     }
 }

app/code/Magento/Sales/Test/Unit/Model/Config/Backend/Email/AsyncSendingTest.php

@@ -63,7 +63,7 @@ protected function setUp()
     public function testAfterSave($value, $oldValue, $eventName)
     {
         $path = 'sales_email/general/async_sending';
-        $scope = \Magento\Framework\App\ScopeInterface::SCOPE_DEFAULT;
+        $scope = \Magento\Framework\App\Config\ScopeConfigInterface::SCOPE_TYPE_DEFAULT;
 
         $this->object->setData(['value' => $value, 'path' => $path, 'scope' => $scope]);
 

app/code/Magento/Sales/Test/Unit/Model/Config/Backend/Grid/AsyncIndexingTest.php

@@ -63,7 +63,7 @@ protected function setUp()
     public function testAfterSave($value, $oldValue, $eventName)
     {
         $path = 'dev/grid/async_indexing';
-        $scope = \Magento\Framework\App\ScopeInterface::SCOPE_DEFAULT;
+        $scope = \Magento\Framework\App\Config\ScopeConfigInterface::SCOPE_TYPE_DEFAULT;
 
         $this->object->setData(['value' => $value, 'path' => $path, 'scope' => $scope]);