Change nonstd::unique_ptr to take a custom deleter.

Code is mostly stolen from Chromium's scoped_ptr.

- Add unit tests.
- Use this to fix a leak.

BUG=chromium:531408
R=jyasskin@chromium.org, tsepez@chromium.org

Review URL: https://codereview.chromium.org/1351383004 .

2 files changed, 12 insertions, 3 deletions

diff --git a/core/include/fxcrt/fx_basic.h b/core/include/fxcrt/fx_basic.h
index bc3d81200f..3e556f5439 100644
--- a/core/include/fxcrt/fx_basic.h
+++ b/core/include/fxcrt/fx_basic.h
@@ -947,6 +947,13 @@ class CFX_AutoRestorer {
   T m_OldValue;
 };
 
+// Used with nonstd::unique_ptr to Release() objects that can't be deleted.
+template <class T>
+struct ReleaseDeleter {
+  inline void operator()(T* ptr) const { ptr->Release(); }
+};
+
+// TODO(thestig) Remove in favor of nonstd::unique_ptr.
 template <class T>
 class CFX_SmartPointer {
  public:
@@ -959,6 +966,7 @@ class CFX_SmartPointer {
  protected:
   T* m_pObj;
 };
+
 #define FX_DATALIST_LENGTH 1024
 template <size_t unit>
 class CFX_SortListArray {
diff --git a/core/src/fpdfapi/fpdf_parser/fpdf_parser_parser.cpp b/core/src/fpdfapi/fpdf_parser/fpdf_parser_parser.cpp
index ff14a984bd..7482f0b8e4 100644
--- a/core/src/fpdfapi/fpdf_parser/fpdf_parser_parser.cpp
+++ b/core/src/fpdfapi/fpdf_parser/fpdf_parser_parser.cpp
@@ -2376,8 +2376,9 @@ CPDF_Object* CPDF_SyntaxParser::GetObjectByStrict(
         continue;
       }
       key = PDF_NameDecode(key);
-      CPDF_Object* pObj = GetObject(pObjList, objnum, gennum);
-      if (pObj == NULL) {
+      nonstd::unique_ptr<CPDF_Object, ReleaseDeleter<CPDF_Object>> obj(
+          GetObject(pObjList, objnum, gennum));
+      if (!obj) {
         if (pDict) {
           pDict->Release();
         }
@@ -2394,7 +2395,7 @@ CPDF_Object* CPDF_SyntaxParser::GetObjectByStrict(
       }
       if (key.GetLength() > 1) {
         pDict->AddValue(CFX_ByteStringC(key.c_str() + 1, key.GetLength() - 1),
-                        pObj);
+                        obj.release());
       }
     }
     if (pContext) {