This works

<?php

namespace Doctrine\Tests\DBAL\Schema\Visitor;

use Doctrine\DBAL\Platforms\AbstractPlatform;
use \Doctrine\DBAL\Schema\Visitor\DropSchemaSqlCollector;

class DropSchemaSqlCollectorTest extends \PHPUnit_Framework_TestCase
{
    public function testGetQueriesUsesAcceptedForeignKeys()
    {
        $tableOne = $this->getMockWithoutArguments('Doctrine\DBAL\Schema\Table');
        $tableTwo = $this->getMockWithoutArguments('Doctrine\DBAL\Schema\Table');

        $keyConstraintOne = $this->getStubKeyConstraint('first');
        $keyConstraintTwo = $this->getStubKeyConstraint('second');

        $platform = $this->getMock('Doctrine\Tests\DBAL\Schema\Visitor\PlatformStub');

        $collector = new DropSchemaSqlCollector($platform);

        $platform->expects($this->exactly(2))
            ->method('getDropForeignKeySQL');

        $platform->expects($this->at(0))
            ->method('getDropForeignKeySQL')
            ->with($keyConstraintOne, $tableOne);

        $platform->expects($this->at(1))
            ->method('getDropForeignKeySQL')
            ->with($keyConstraintTwo, $tableTwo);

        $collector->acceptForeignKey($tableOne, $keyConstraintOne);
        $collector->acceptForeignKey($tableTwo, $keyConstraintTwo);

        $collector->getQueries();
    }

    private function getMockWithoutArguments($className)
    {
        return $this->getMockBuilder($className)->disableOriginalConstructor()->getMock();
    }

    private function getStubKeyConstraint($name)
    {
        $constraint = $this->getMockWithoutArguments('Doctrine\DBAL\Schema\ForeignKeyConstraint');

        $constraint->expects($this->any())
            ->method('getName')
            ->will($this->returnValue($name));

        return $constraint;
    }
}

class PlatformStub extends AbstractPlatform {

    /**
     * Returns the SQL snippet that declares a boolean column.
     *
     * @param array $columnDef
     *
     * @return string
     */
    public function getBooleanTypeDeclarationSQL( array $columnDef ) {
        // TODO: Implement getBooleanTypeDeclarationSQL() method.
    }

    /**
     * Returns the SQL snippet that declares a 4 byte integer column.
     *
     * @param array $columnDef
     *
     * @return string
     */
    public function getIntegerTypeDeclarationSQL( array $columnDef ) {
        // TODO: Implement getIntegerTypeDeclarationSQL() method.
    }

    /**
     * Returns the SQL snippet that declares an 8 byte integer column.
     *
     * @param array $columnDef
     *
     * @return string
     */
    public function getBigIntTypeDeclarationSQL( array $columnDef ) {
        // TODO: Implement getBigIntTypeDeclarationSQL() method.
    }

    /**
     * Returns the SQL snippet that declares a 2 byte integer column.
     *
     * @param array $columnDef
     *
     * @return string
     */
    public function getSmallIntTypeDeclarationSQL( array $columnDef ) {
        // TODO: Implement getSmallIntTypeDeclarationSQL() method.
    }

    /**
     * Returns the SQL snippet that declares common properties of an integer column.
     *
     * @param array $columnDef
     *
     * @return string
     */
    protected function _getCommonIntegerTypeDeclarationSQL( array $columnDef ) {
        // TODO: Implement _getCommonIntegerTypeDeclarationSQL() method.
    }

    /**
     * Lazy load Doctrine Type Mappings.
     *
     * @return void
     */
    protected function initializeDoctrineTypeMappings() {
        // TODO: Implement initializeDoctrineTypeMappings() method.
    }

    /**
     * Returns the SQL snippet used to declare a CLOB column type.
     *
     * @param array $field
     *
     * @return string
     */
    public function getClobTypeDeclarationSQL( array $field ) {
        // TODO: Implement getClobTypeDeclarationSQL() method.
    }

    /**
     * Returns the SQL Snippet used to declare a BLOB column type.
     *
     * @param array $field
     *
     * @return string
     */
    public function getBlobTypeDeclarationSQL( array $field ) {
        // TODO: Implement getBlobTypeDeclarationSQL() method.
    }

    /**
     * Gets the name of the platform.
     *
     * @return string
     */
    public function getName() {
        // TODO: Implement getName() method.
    }
}