minor #39775 [WIP] Use ::class keyword when possible (fabpot)

This PR was merged into the 4.4 branch.

Discussion
----------

[WIP] Use ::class keyword when possible

| Q             | A
| ------------- | ---
| Branch?       | 4.4 <!-- see below -->
| Bug fix?      | no
| New feature?  | no <!-- please update src/**/CHANGELOG.md files -->
| Deprecations? | no <!-- please update UPGRADE-*.md and src/**/CHANGELOG.md files -->
| Tickets       | n/a  <!-- prefix each issue number with "Fix #", no need to create an issue if none exist, explain below instead -->
| License       | MIT
| Doc PR        | n/a

Commits
-------

036a36cb14 Use ::class keyword when possible

Author: fabpot

Core/Tests/Authentication/Token/AbstractTokenTest.php

@@ -134,7 +134,7 @@ public function testAttributes()
             $token->getAttribute('foobar');
             $this->fail('->getAttribute() throws an \InvalidArgumentException exception when the attribute does not exist');
         } catch (\Exception $e) {
-            $this->assertInstanceOf('\InvalidArgumentException', $e, '->getAttribute() throws an \InvalidArgumentException exception when the attribute does not exist');
+            $this->assertInstanceOf(\InvalidArgumentException::class, $e, '->getAttribute() throws an \InvalidArgumentException exception when the attribute does not exist');
             $this->assertEquals('This token has no "foobar" attribute.', $e->getMessage(), '->getAttribute() throws an \InvalidArgumentException exception when the attribute does not exist');
         }
     }

Http/Tests/Firewall/RememberMeListenerTest.php

@@ -13,12 +13,14 @@
 
 use PHPUnit\Framework\TestCase;
 use Symfony\Component\HttpFoundation\Request;
+use Symfony\Component\HttpFoundation\Session\SessionInterface;
 use Symfony\Component\HttpKernel\Event\RequestEvent;
 use Symfony\Component\HttpKernel\Event\ResponseEvent;
 use Symfony\Component\HttpKernel\HttpKernelInterface;
 use Symfony\Component\Security\Core\Exception\AuthenticationException;
 use Symfony\Component\Security\Http\Firewall\RememberMeListener;
 use Symfony\Component\Security\Http\SecurityEvents;
+use Symfony\Component\Security\Http\Session\SessionAuthenticationStrategyInterface;
 use Symfony\Contracts\EventDispatcher\EventDispatcherInterface;
 
 class RememberMeListenerTest extends TestCase
@@ -227,7 +229,7 @@ public function testSessionStrategy()
             ->willReturn($token)
         ;
 
-        $session = $this->getMockBuilder('\Symfony\Component\HttpFoundation\Session\SessionInterface')->getMock();
+        $session = $this->getMockBuilder(SessionInterface::class)->getMock();
         $session
             ->expects($this->once())
             ->method('isStarted')
@@ -277,7 +279,7 @@ public function testSessionIsMigratedByDefault()
             ->willReturn($token)
         ;
 
-        $session = $this->getMockBuilder('\Symfony\Component\HttpFoundation\Session\SessionInterface')->getMock();
+        $session = $this->getMockBuilder(SessionInterface::class)->getMock();
         $session
             ->expects($this->once())
             ->method('isStarted')
@@ -402,6 +404,6 @@ protected function getDispatcher()
 
     private function getSessionStrategy()
     {
-        return $this->getMockBuilder('\Symfony\Component\Security\Http\Session\SessionAuthenticationStrategyInterface')->getMock();
+        return $this->getMockBuilder(SessionAuthenticationStrategyInterface::class)->getMock();
     }
 }