Deal with ca and CA transparency operators in pdf. add comments to generated classes.

experimental/PdfViewer/SkPdfAttributeObjectDictionary_autogen.h

 #ifndef __DEFINED__SkPdfAttributeObjectDictionary
 #define __DEFINED__SkPdfAttributeObjectDictionary
 
 #include "SkPdfEnums_autogen.h"
 #include "SkPdfArray_autogen.h"
 #include "SkPdfDictionary_autogen.h"
 
+// Entry common to all attribute objects
 class SkPdfAttributeObjectDictionary : public SkPdfDictionary {
 public:
   virtual SkPdfObjectType getType() const { return kAttributeObjectDictionary_SkPdfObjectType;}
   virtual SkPdfObjectType getTypeEnd() const { return (SkPdfObjectType)(kAttributeObjectDictionary_SkPdfObjectType + 1);}
 public:
   virtual SkPdfAttributeObjectDictionary* asAttributeObjectDictionary() {return this;}
   virtual const SkPdfAttributeObjectDictionary* asAttributeObjectDictionary() const {return this;}
 
 private:
   virtual SkPdfALinkAnnotationDictionary* asALinkAnnotationDictionary() {return NULL;}
@@ skipping 496 matching lines @@
 
 public:
 private:
 public:
   SkPdfAttributeObjectDictionary(const PdfMemDocument* podofoDoc = NULL, const PdfObject* podofoObj = NULL) : SkPdfDictionary(podofoDoc, podofoObj) {}
 
   virtual bool valid() const {return true;}
 
   SkPdfAttributeObjectDictionary& operator=(const SkPdfAttributeObjectDictionary& from) {this->fPodofoDoc = from.fPodofoDoc; this->fPodofoObj = from.fPodofoObj; return *this;}
 
+/** (Required) The name of the application or plug-in extension owning the attribute data.
+ *  The name must conform to the guidelines described in Appendix E.
+**/
+  bool has_O() const {
+    return (ObjectFromDictionary(fPodofoDoc, fPodofoObj->GetDictionary(), "O", "", NULL));
+  }
+
   std::string O() const {
     std::string ret;
     if (NameFromDictionary(fPodofoDoc, fPodofoObj->GetDictionary(), "O", "", &ret)) return ret;
     // TODO(edisonn): warn about missing required field, assert for known good pdfs
     return "";
   }
 
 };
 
 #endif  // __DEFINED__SkPdfAttributeObjectDictionary