SKPDF: refactor pdfcatalog and pdfdocument

SkPDFCatalog:
-   remove first-page-specific code (no longer needed, never
    used) (e.g. addObject()).
-   Make use of SkHashMap for lookups (simplifies code).
-   inline all small methods
-   emitXrefTable moved to SkPDFDocument.cpp
-   no longer store offsets in this data structure (moved to
    SkPDFDocument.cpp)
-   setFileOffset gone.
-   own substitute refs directly.

SkPDFDocument::EmitPDF()
-   All sites that call into SkPDFCatalog modified.
-   catalog.addObject only called in a single place, after the
    resouceSet is built
-   offsets moved to local array.

SkPDFPage:
-   finalizePage no longer deals with SkPDFCatalog or resource sets.
-   GeneratePageTree no longer deals with SkPDFCatalog

SkPDFObjRef
-   emitObject respects the substitution map

Unit Tests:
-   respect SkPDFCatalog::addObject signature change.

SkTHash:
-   #include SkChecksum for SkGoodHash
-   Copyright notice added

Review URL: https://codereview.chromium.org/1033543002

1 files changed, 2 insertions, 1 deletions

diff --git a/src/pdf/SkPDFTypes.cpp b/src/pdf/SkPDFTypes.cpp
index 43cd68450f..8bb19360e1 100644
--- a/src/pdf/SkPDFTypes.cpp
+++ b/src/pdf/SkPDFTypes.cpp
@@ -26,7 +26,8 @@ SkPDFObjRef::SkPDFObjRef(SkPDFObject* obj) : fObj(obj) {
 SkPDFObjRef::~SkPDFObjRef() {}
 
 void SkPDFObjRef::emitObject(SkWStream* stream, SkPDFCatalog* catalog) {
-    stream->writeDecAsText(catalog->getObjectNumber(fObj.get()));
+    SkPDFObject* obj = catalog->getSubstituteObject(fObj);
+    stream->writeDecAsText(catalog->getObjectNumber(obj));
     stream->writeText(" 0 R");  // Generation number is always 0.
 }