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

experimental/PdfViewer/SkPdfSoftMaskImageDictionary_autogen.h

 #ifndef __DEFINED__SkPdfSoftMaskImageDictionary
 #define __DEFINED__SkPdfSoftMaskImageDictionary
 
 #include "SkPdfEnums_autogen.h"
 #include "SkPdfArray_autogen.h"
 #include "SkPdfDictionary_autogen.h"
 
+// Additional entry in a soft-mask image dictionary
 class SkPdfSoftMaskImageDictionary : public SkPdfDictionary {
 public:
   virtual SkPdfObjectType getType() const { return kSoftMaskImageDictionary_SkPdfObjectType;}
   virtual SkPdfObjectType getTypeEnd() const { return (SkPdfObjectType)(kSoftMaskImageDictionary_SkPdfObjectType + 1);}
 public:
   virtual SkPdfSoftMaskImageDictionary* asSoftMaskImageDictionary() {return this;}
   virtual const SkPdfSoftMaskImageDictionary* asSoftMaskImageDictionary() const {return this;}
 
 private:
   virtual SkPdfALinkAnnotationDictionary* asALinkAnnotationDictionary() {return NULL;}
@@ skipping 496 matching lines @@
 
 public:
 private:
 public:
   SkPdfSoftMaskImageDictionary(const PdfMemDocument* podofoDoc = NULL, const PdfObject* podofoObj = NULL) : SkPdfDictionary(podofoDoc, podofoObj) {}
 
   virtual bool valid() const {return true;}
 
   SkPdfSoftMaskImageDictionary& operator=(const SkPdfSoftMaskImageDictionary& from) {this->fPodofoDoc = from.fPodofoDoc; this->fPodofoObj = from.fPodofoObj; return *this;}
 
+/** (Optional; PDF 1.4) An array of component values specifying the matte color with
+ *  which the image data in the parent image has been preblended. The array consists of n
+ *  numbers, where n is the number of components in the color space specified by the
+ *  ColorSpace entry in the parent image's image dictionary; the numbers must be valid
+ *  color components in that color space. If this entry is absent, the image data is not pre-
+ *  blended.
+**/
+  bool has_Matte() const {
+    return (ObjectFromDictionary(fPodofoDoc, fPodofoObj->GetDictionary(), "Matte", "", NULL));
+  }
+
   SkPdfArray Matte() const {
     SkPdfArray ret;
     if (ArrayFromDictionary(fPodofoDoc, fPodofoObj->GetDictionary(), "Matte", "", &ret)) return ret;
     // TODO(edisonn): warn about missing required field, assert for known good pdfs
     return SkPdfArray();
   }
 
 };
 
 #endif  // __DEFINED__SkPdfSoftMaskImageDictionary