MAGETWO-36378: Magento\Quote\Api\GuestCartManagement

 - Remove \Magento\Quote\Model\GuestCart\GuestCartManagement::getCartForCustomer
 - Remove associated unit test case

app/code/Magento/Quote/Model/GuestCart/GuestCartManagement.php

@@ -84,16 +84,4 @@ class GuestCartManagement implements GuestCartManagementInterface
         $quoteIdMask = $this->quoteIdMaskFactory->create()->load($cartId, 'masked_id');
         return $this->quoteManagement->placeOrder($quoteIdMask->getId());
     }
-
-    /**
-     * {@inheritdoc}
-     */
-    public function getCartForCustomer($customerId)
-    {
-        $cart = $this->quoteRepository->getActiveForCustomer($customerId);
-        /** @var $quoteIdMask QuoteIdMask */
-        $quoteIdMask = $this->quoteIdMaskFactory->create()->load($cart->getId(), 'masked_id');
-        $cart->setId($quoteIdMask->getId());
-        return $cart;
-    }
 }

app/code/Magento/Quote/Test/Unit/Model/GuestCart/GuestCartManagementTest.php

@@ -115,18 +115,4 @@ class GuestCartManagementTest extends \PHPUnit_Framework_TestCase
 
         $this->assertEquals($orderId, $this->guestCartManagement->placeOrder($cartId));
     }
-
-    public function testGetCartForCustomer()
-    {
-        $maskedCartId = 'masked1cart2id3';
-        $cartId = 1;
-        $orderId = 1;
-
-        $this->quoteIdMaskMock->expects($this->once())->method('load')->with($cartId, 'masked_id')->willReturnSelf();
-        $this->quoteIdMaskMock->expects($this->once())->method('getId')->willReturn($maskedCartId);
-        $this->quoteIdMaskFactoryMock->expects($this->once())->method('create')->willReturn($this->quoteIdMaskMock);
-        $this->quoteManagementMock->expects($this->once())->method('placeOrder')->willReturn($orderId);
-
-        $this->assertEquals($orderId, $this->guestCartManagement->placeOrder($cartId));
-    }
 }