pdfviewer: add indexed rbg image support, enhanche caching(setData) for SkPdfObject

experimental/PdfViewer/SkPdfFont.cpp

 #include "SkPdfFont.h"
 
 #include "SkStream.h"
 #include "SkTypeface.h"
 #include "SkPdfNativeTokenizer.h"
 
 std::map<std::string, SkPdfStandardFontEntry>& getStandardFonts() {
     static std::map<std::string, SkPdfStandardFontEntry> gPdfStandardFonts;
 
     // TODO (edisonn): , vs - ? what does it mean?
@@ skipping 237 matching lines @@
             // TODO(edisonn): report error?
             return NULL;
     }
 }
 
 SkPdfFont* SkPdfFont::fontFromPdfDictionary(SkNativeParsedPDF* doc, SkPdfFontDictionary* dict) {
     if (dict == NULL) {
         return NULL;  // TODO(edisonn): report default one?
     }
 
-    if (dict->data() == NULL) {
-        dict->setData(fontFromPdfDictionaryOnce(doc, dict));
+    if (!dict->hasData(SkPdfObject::kFont_Data)) {
+        dict->setData(fontFromPdfDictionaryOnce(doc, dict), SkPdfObject::kFont_Data);
     }
-    return (SkPdfFont*)dict->data();
+    return (SkPdfFont*)dict->data(SkPdfObject::kFont_Data);
 }
 
 
 
 SkPdfType0Font* SkPdfFont::fontFromType0FontDictionary(SkNativeParsedPDF* doc, SkPdfType0FontDictionary* dict) {
     if (dict == NULL) {
         return NULL;  // default one?
     }
 
     return new SkPdfType0Font(doc, dict);
@@ skipping 173 matching lines @@
 SkPdfEncoding* SkPdfEncoding::fromName(const char* name) {
     SkPdfEncoding* encoding = getStandardEncodings()[name];
 
 #ifdef PDF_TRACE
     if (encoding == NULL) {
         printf("Encoding not found: %s\n", name);
     }
 #endif
     return encoding;
 }