SkPDF: draw{Image,Bitmap} always serializes early

src/pdf/SkPDFDocument.cpp

Index: src/pdf/SkPDFDocument.cpp
diff --git a/src/pdf/SkPDFDocument.cpp b/src/pdf/SkPDFDocument.cpp
index 8e884d5e834f20e5859a57ea0a3963168be92733..cf312e55fbc3c171b7c7121719066872ed244295 100644
--- a/src/pdf/SkPDFDocument.cpp
+++ b/src/pdf/SkPDFDocument.cpp
@@ -14,11 +14,16 @@
 #include "SkPDFUtils.h"
 #include "SkStream.h"
 
-
 SkPDFObjectSerializer::SkPDFObjectSerializer() : fBaseOffset(0), fNextToBeSerialized(0) {}
 
 template <class T> static void renew(T* t) { t->~T(); new (t) T; }
 
+SkPDFObjectSerializer::~SkPDFObjectSerializer() {
+    for (int i = 0; i < fObjNumMap.objects().count(); ++i) {
+        fObjNumMap.objects()[i]->drop();
+    }
+}
+
 void SkPDFObjectSerializer::addObjectRecursively(const sk_sp<SkPDFObject>& object) {
     fObjNumMap.addObjectRecursively(object.get(), fSubstituteMap);
 }