Fix leaks in the embedder tests themselves.

core/src/fpdfapi/fpdf_parser/fpdf_parser_parser_embeddertest.cpp

 // Copyright 2015 PDFium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "../../../testing/embedder_test.h"
 #include "testing/gtest/include/gtest/gtest.h"
 
 class FPDFParserEmbeddertest : public EmbedderTest {
 };
 
 TEST_F(FPDFParserEmbeddertest, LoadError_454695) {
   // Test trailer dictionary with $$ze instead of Size.
   EXPECT_TRUE(OpenDocument("testing/resources/bug_454695.pdf"));
 }
 
 TEST_F(FPDFParserEmbeddertest, Bug_481363) {
   // Test colorspace object with malformed dictionary.
   EXPECT_TRUE(OpenDocument("testing/resources/bug_481363.pdf"));
-  EXPECT_NE(nullptr, LoadPage(0));
+  FPDF_PAGE page = LoadPage(0);
+  EXPECT_NE(nullptr, page);
+  UnloadPage(page);
 }