Remove unnecessary includes in src/pdf/

src/pdf/SkPDFResourceDict.h

 /*
  * Copyright 2013 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #ifndef SkPDFResourceDict_DEFINED
 #define SkPDFResourceDict_DEFINED
 
-#include "SkPDFTypes.h"
+#include "SkRefCnt.h"
 #include "SkTDArray.h"
-#include "SkTypes.h"
+
+class SkPDFDict;
+class SkPDFObject;
 
 /** \class SkPDFResourceDict
 
     A resource dictionary, which maintains the relevant sub-dicts and
     allows generation of a list of referenced SkPDFObjects inserted with
     insertResourceAsRef.
 */
 class SkPDFResourceDict {
 public:
     enum SkPDFResourceType {
@@ skipping 23 matching lines @@
      * dict.
      *
      *  @param type  The type of resource being entered, like
      *    kPattern_ResourceType or kExtGState_ResourceType.
      *  @param key   The resource key, should be unique within its type.
      */
     static SkString getResourceName(SkPDFResourceType type, int key);
 };
 
 #endif