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

experimental/PdfViewer/SkPdfAlternateImageDictionary_autogen.h

 #ifndef __DEFINED__SkPdfAlternateImageDictionary
 #define __DEFINED__SkPdfAlternateImageDictionary
 
 #include "SkPdfEnums_autogen.h"
 #include "SkPdfArray_autogen.h"
 #include "SkPdfDictionary_autogen.h"
 
+// Entries in an alternate image dictionary
 class SkPdfAlternateImageDictionary : public SkPdfDictionary {
 public:
   virtual SkPdfObjectType getType() const { return kAlternateImageDictionary_SkPdfObjectType;}
   virtual SkPdfObjectType getTypeEnd() const { return (SkPdfObjectType)(kAlternateImageDictionary_SkPdfObjectType + 1);}
 public:
   virtual SkPdfAlternateImageDictionary* asAlternateImageDictionary() {return this;}
   virtual const SkPdfAlternateImageDictionary* asAlternateImageDictionary() const {return this;}
 
 private:
   virtual SkPdfALinkAnnotationDictionary* asALinkAnnotationDictionary() {return NULL;}
@@ skipping 496 matching lines @@
 
 public:
 private:
 public:
   SkPdfAlternateImageDictionary(const PdfMemDocument* podofoDoc = NULL, const PdfObject* podofoObj = NULL) : SkPdfDictionary(podofoDoc, podofoObj) {}
 
   virtual bool valid() const {return true;}
 
   SkPdfAlternateImageDictionary& operator=(const SkPdfAlternateImageDictionary& from) {this->fPodofoDoc = from.fPodofoDoc; this->fPodofoObj = from.fPodofoObj; return *this;}
 
+/** (Required) The image XObject for the alternate image.
+**/
+  bool has_Image() const {
+    return (ObjectFromDictionary(fPodofoDoc, fPodofoObj->GetDictionary(), "Image", "", NULL));
+  }
+
   SkPdfStream Image() const {
     SkPdfStream ret;
     if (StreamFromDictionary(fPodofoDoc, fPodofoObj->GetDictionary(), "Image", "", &ret)) return ret;
     // TODO(edisonn): warn about missing required field, assert for known good pdfs
     return SkPdfStream();
   }
 
+/** (Optional) A flag indicating whether this alternate image is the default ver-
+ *  sion to be used for printing. At most one alternate for a given base image may
+ *  be so designated. If no alternate has this entry set to true, the base image itself
+ *  is used for printing.
+**/
+  bool has_DefaultForPrinting() const {
+    return (ObjectFromDictionary(fPodofoDoc, fPodofoObj->GetDictionary(), "DefaultForPrinting", "", NULL));
+  }
+
   bool DefaultForPrinting() const {
     bool ret;
     if (BoolFromDictionary(fPodofoDoc, fPodofoObj->GetDictionary(), "DefaultForPrinting", "", &ret)) return ret;
     // TODO(edisonn): warn about missing required field, assert for known good pdfs
     return false;
   }
 
 };
 
 #endif  // __DEFINED__SkPdfAlternateImageDictionary