Convert pdfium::MakeUnique<> to std::make_unique<> in fpdfsdk

Use C++14 features.

-- ensure <memory> included in .cpp or corresponding .h file
-- remove ptr_util.h include unless WrapUnique() (3 cases).

Change-Id: I319cdb33ccadf94421edbeff5ea43e0e7cffa1c4
Reviewed-on: https://pdfium-review.googlesource.com/c/pdfium/+/69955
Reviewed-by: Lei Zhang <thestig@chromium.org>
Commit-Queue: Tom Sepez <tsepez@chromium.org>
diff --git a/fpdfsdk/fpdf_editimg.cpp b/fpdfsdk/fpdf_editimg.cpp
index 1e0e560..7637bf9 100644
--- a/fpdfsdk/fpdf_editimg.cpp
+++ b/fpdfsdk/fpdf_editimg.cpp
@@ -6,6 +6,7 @@
 
 #include "public/fpdf_edit.h"
 
+#include <memory>
 #include <utility>
 
 #include "core/fpdfapi/page/cpdf_dib.h"
@@ -19,7 +20,6 @@
 #include "core/fpdfapi/parser/cpdf_stream_acc.h"
 #include "fpdfsdk/cpdfsdk_customaccess.h"
 #include "fpdfsdk/cpdfsdk_helpers.h"
-#include "third_party/base/ptr_util.h"
 
 namespace {
 
@@ -95,7 +95,7 @@
   if (!pDoc)
     return nullptr;
 
-  auto pImageObj = pdfium::MakeUnique<CPDF_ImageObject>();
+  auto pImageObj = std::make_unique<CPDF_ImageObject>();
   pImageObj->SetImage(pdfium::MakeRetain<CPDF_Image>(pDoc));
 
   // Caller takes ownership.