refactoring for pdf viewer lib

experimental/PdfViewer/SkPdfBasics.h

 #ifndef __DEFINED__SkPdfBasics
 #define __DEFINED__SkPdfBasics
 
 #include "podofo.h"
 using namespace PoDoFo;
 
+#include "SkCanvas.h"
+#include "SkPaint.h"
+
 #include <iostream>
 #include <cstdio>
 #include <stack>
 
 //#define PDF_TRACE
 //#define PDF_TRACE_DIFF_IN_PNG
 //#define PDF_DEBUG_NO_CLIPING
 //#define PDF_DEBUG_NO_PAGE_CLIPING
 //#define PDF_DEBUG_3X
 
 class SkPdfFont;
 class SkPdfDoc;
+class SkPdfObject;
+class SkPdfResourceDictionary;
 
 // TODO(edisonn): better class design.
 struct PdfColorOperator {
     std::string fColorSpace;  // TODO(edisonn): use SkString
     SkColor fColor;
     double fOpacity;  // ca or CA
     // TODO(edisonn): add here other color space options.
 
     void setRGBColor(SkColor color) {
         // TODO(edisonn): ASSERT DeviceRGB is the color space.
@@ skipping 98 matching lines @@
     kPartial_PdfResult,
     kNYI_PdfResult,
     kIgnoreError_PdfResult,
     kError_PdfResult,
     kUnsupported_PdfResult,
 
     kCount_PdfResult
 };
 
 #endif  // __DEFINED__SkPdfBasics