remove now all the files fro depot for PDF API since we generate them at build time

experimental/PdfViewer/pdfparser/podofo/autogen/SkPdfThreadDictionary_autogen.cpp

-#include "SkPdfThreadDictionary_autogen.h"
-
-std::string SkPdfThreadDictionary::Type() const {
-  std::string ret;
-  if (NameFromDictionary(fPodofoDoc, fPodofoObj->GetDictionary(), "Type", "", &ret)) return ret;
-  // TODO(edisonn): warn about missing required field, assert for known good pdfs
-  return "";
-}
-
-SkPdfDictionary* SkPdfThreadDictionary::F() const {
-  SkPdfDictionary* ret;
-  if (DictionaryFromDictionary(fPodofoDoc, fPodofoObj->GetDictionary(), "F", "", &ret)) return ret;
-  // TODO(edisonn): warn about missing required field, assert for known good pdfs
-  return NULL;
-}
-
-SkPdfDictionary* SkPdfThreadDictionary::I() const {
-  SkPdfDictionary* ret;
-  if (DictionaryFromDictionary(fPodofoDoc, fPodofoObj->GetDictionary(), "I", "", &ret)) return ret;
-  // TODO(edisonn): warn about missing required field, assert for known good pdfs
-  return NULL;
-}