Reland "Remove CPDF_Object::Release() in favor of direct delete"

This reverts commit f0d5b6c35fa343108a3ab7a25bc2cc2b3cf105b3.

Review-Url: https://codereview.chromium.org/2478303002
diff --git a/fpdfsdk/fpdfdoc_unittest.cpp b/fpdfsdk/fpdfdoc_unittest.cpp
index 408d2fa..39e81d5 100644
--- a/fpdfsdk/fpdfdoc_unittest.cpp
+++ b/fpdfsdk/fpdfdoc_unittest.cpp
@@ -87,7 +87,7 @@
  protected:
   std::unique_ptr<CPDF_TestPdfDocument> m_pDoc;
   CPDF_IndirectObjectHolder* m_pIndirectObjs;
-  std::unique_ptr<CPDF_Dictionary, ReleaseDeleter<CPDF_Dictionary>> m_pRootObj;
+  std::unique_ptr<CPDF_Dictionary> m_pRootObj;
 };
 
 TEST_F(PDFDocTest, FindBookmark) {