pdfviewer: remove dependency on picture_utils. add utility function to render SkStream into bitmap.

experimental/PdfViewer/SkPdfRenderer.h

 /*
  * Copyright 2013 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 
 #ifndef SkPdfRenderer_DEFINED
 #define SkPdfRenderer_DEFINED
 
+class SkBitmap;
 class SkCanvas;
 class SkNativeParsedPDF;
 class SkRect;
+class SkStream;
+
+enum SkPdfContent {
+    kNoForms_SkPdfContent,
+    kAll_SkPdfContent,
+};
 
 // TODO(edisonn): move in another file
 class SkPdfRenderer : public SkRefCnt {
     SkNativeParsedPDF* fPdfDoc;
 public:
     SkPdfRenderer() : fPdfDoc(NULL) {}
     virtual ~SkPdfRenderer() {unload();}
 
     // TODO(edisonn): add options to render forms, or not
     bool renderPage(int page, SkCanvas* canvas, const SkRect& dst) const;
 
     bool load(const SkString inputFileName);
+    bool load(SkStream* stream);
     bool loaded() const {return fPdfDoc != NULL;}
     int pages() const;
     void unload();
     SkRect MediaBox(int page) const;
     size_t bytesUsed() const;
 };
 
 void reportPdfRenderStats();
 
+bool SkPDFNativeRenderToBitmap(SkStream* stream,
+                               SkBitmap* output,
+                               int page = 0,
+                               SkPdfContent content = kAll_SkPdfContent,
+                               double dpi = 72.0);
+
 #endif  // SkPdfRenderer_DEFINED