SkPDF: PDFStream has-a not is-a PDFDict

Motivation:
SkPDFStream and SkPDFSharedStream now work the same.

Also:
- move SkPDFStream into SkPDFTypes (it's a fundamental PDF type).
- minor refactor of SkPDFSharedStream
- SkPDFSharedStream takes unique_ptr to represent ownership

BUG=skia:
GOLD_TRYBOT_URL= https://gold.skia.org/search?issue=2190883003

Review-Url: https://codereview.chromium.org/2190883003

1 files changed, 46 insertions, 5 deletions

diff --git a/src/pdf/SkPDFTypes.h b/src/pdf/SkPDFTypes.h
index 5e4de3a259..6ee9162139 100644
--- a/src/pdf/SkPDFTypes.h
+++ b/src/pdf/SkPDFTypes.h
@@ -14,6 +14,7 @@
 #include "SkTHash.h"
 #include "SkTypes.h"
 
+class SkData;
 class SkPDFObjNumMap;
 class SkPDFObject;
 class SkPDFSubstituteMap;
@@ -307,10 +308,9 @@ private:
  */
 class SkPDFSharedStream final : public SkPDFObject {
 public:
-    // Takes ownership of asset.
-    SkPDFSharedStream(SkStreamAsset* data);
+    SkPDFSharedStream(std::unique_ptr<SkStreamAsset> data);
     ~SkPDFSharedStream();
-    SkPDFDict* dict() { return fDict.get(); }
+    SkPDFDict* dict() { return &fDict; }
     void emitObject(SkWStream*,
                     const SkPDFObjNumMap&,
                     const SkPDFSubstituteMap&) const override;
@@ -320,11 +320,52 @@ public:
 
 private:
     std::unique_ptr<SkStreamAsset> fAsset;
-    sk_sp<SkPDFDict> fDict;
-    SkDEBUGCODE(bool fDumped;)
+    SkPDFDict fDict;
     typedef SkPDFObject INHERITED;
 };
 
+/** \class SkPDFStream
+
+    This class takes an asset and assumes that it is the only owner of
+    the asset's data.  It immediately compresses the asset to save
+    memory.
+ */
+
+class SkPDFStream : public SkPDFObject {
+
+public:
+    /** Create a PDF stream. A Length entry is automatically added to the
+     *  stream dictionary.
+     *  @param data   The data part of the stream.
+     *  @param stream The data part of the stream. */
+    explicit SkPDFStream(sk_sp<SkData> data);
+    explicit SkPDFStream(std::unique_ptr<SkStreamAsset> stream);
+    virtual ~SkPDFStream();
+
+    SkPDFDict* dict() { return &fDict; }
+
+    // The SkPDFObject interface.
+    void emitObject(SkWStream* stream,
+                    const SkPDFObjNumMap& objNumMap,
+                    const SkPDFSubstituteMap& substitutes) const override;
+    void addResources(SkPDFObjNumMap*, const SkPDFSubstituteMap&) const final;
+    void drop() override;
+
+protected:
+    /* Create a PDF stream with no data.  The setData method must be called to
+     * set the data. */
+    SkPDFStream();
+
+    /** Only call this function once. */
+    void setData(std::unique_ptr<SkStreamAsset> stream);
+
+private:
+    std::unique_ptr<SkStreamAsset> fCompressedData;
+    SkPDFDict fDict;
+
+    typedef SkPDFDict INHERITED;
+};
+
 ////////////////////////////////////////////////////////////////////////////////
 
 /** \class SkPDFObjNumMap