SkPDF: remove all globally references SkPDFObjects

Move these singletons into SkPDFCanon (there is still a single object
per document; output PDF size will not change).

Motivation: After this change, all indirectly-referenced SkPDFObjects
are serialized exactly once.  The next CL will add a memory saving
feature: a method to purge an object's resources immediately after
serialization.  After that, further changes wil allow some objects to be
serialized *before* SkDocument::close(), leading to potentially very
large memory savings.

BUG=skia:5087
GOLD_TRYBOT_URL= https://gold.skia.org/search2?unt=true&query=source_type%3Dgm&master=false&issue=1788263002

Review URL: https://codereview.chromium.org/1788263002

1 files changed, 22 insertions, 0 deletions

diff --git a/src/pdf/SkPDFCanon.cpp b/src/pdf/SkPDFCanon.cpp
index 4fdaa0db62..d7aea8ad69 100644
--- a/src/pdf/SkPDFCanon.cpp
+++ b/src/pdf/SkPDFCanon.cpp
@@ -149,3 +149,25 @@ const SkImage* SkPDFCanon::bitmapToImage(const SkBitmap& bm) {
     bm.copyTo(&n32bitmap, kN32_SkColorType);
     return *fBitmapToImageMap.set(key, SkImage::NewFromBitmap(n32bitmap));
 }
+
+sk_sp<SkPDFStream> SkPDFCanon::makeInvertFunction() {
+    if (fInvertFunction) {
+        return fInvertFunction;
+    }
+    fInvertFunction = SkPDFGraphicState::MakeInvertFunction();
+    return fInvertFunction;
+}
+sk_sp<SkPDFDict> SkPDFCanon::makeNoSmaskGraphicState() {
+    if (fNoSmaskGraphicState) {
+        return fNoSmaskGraphicState;
+    }
+    fNoSmaskGraphicState = SkPDFGraphicState::MakeNoSmaskGraphicState();
+    return fNoSmaskGraphicState;
+}
+sk_sp<SkPDFArray> SkPDFCanon::makeRangeObject() {
+    if (fRangeObject) {
+        return fRangeObject;
+    }
+    fRangeObject = SkPDFShader::MakeRangeObject();
+    return fRangeObject;
+}