Simplify reference management in SkPDF

src/pdf/SkPDFFormXObject.cpp

Index: src/pdf/SkPDFFormXObject.cpp
diff --git a/src/pdf/SkPDFFormXObject.cpp b/src/pdf/SkPDFFormXObject.cpp
index 2a0f5306efb7bd4e945926a7ef3d46a60143d964..48d182eb405f0de4c1bed6e5060069e67c7684e0 100644
--- a/src/pdf/SkPDFFormXObject.cpp
+++ b/src/pdf/SkPDFFormXObject.cpp
@@ -21,9 +21,7 @@ SkPDFFormXObject::SkPDFFormXObject(SkPDFDevice* device) {
     // We don't want to keep around device because we'd have two copies
     // of content, so reference or copy everything we need (content and
     // resources).
-    SkTSet<SkPDFObject*> emptySet;
     SkPDFResourceDict* resourceDict = device->getResourceDict();
-    resourceDict->getReferencedResources(emptySet, &fResources, false);
 
     SkAutoTDelete<SkStream> content(device->content());
     setData(content.get());
@@ -50,9 +48,6 @@ SkPDFFormXObject::SkPDFFormXObject(SkPDFDevice* device) {
  */
 SkPDFFormXObject::SkPDFFormXObject(SkStream* content, SkRect bbox,
                                    SkPDFResourceDict* resourceDict) {
-    SkTSet<SkPDFObject*> emptySet;
-    resourceDict->getReferencedResources(emptySet, &fResources, false);
-
     setData(content);
 
     SkAutoTUnref<SkPDFArray> bboxArray(SkPDFUtils::RectToArray(bbox));
@@ -82,14 +77,4 @@ void SkPDFFormXObject::init(const char* colorSpace,
     insert("Group", group.get());
 }
 
-SkPDFFormXObject::~SkPDFFormXObject() {
-    fResources.unrefAll();
-}
-
-void SkPDFFormXObject::getResources(
-        const SkTSet<SkPDFObject*>& knownResourceObjects,
-        SkTSet<SkPDFObject*>* newResourceObjects) {
-    GetResourcesHelper(&fResources.toArray(),
-                       knownResourceObjects,
-                       newResourceObjects);
-}
+SkPDFFormXObject::~SkPDFFormXObject() {}