SkDocument/PDF: new API

has a pdf/a switch.
sets metadata in factory.

BUG=skia:
GOLD_TRYBOT_URL= https://gold.skia.org/search2?unt=true&query=source_type%3Dgm&master=false&issue=1916093002

Review URL: https://codereview.chromium.org/1916093002
diff --git a/tests/PDFPrimitivesTest.cpp b/tests/PDFPrimitivesTest.cpp
index 299fcf0..58dd773 100644
--- a/tests/PDFPrimitivesTest.cpp
+++ b/tests/PDFPrimitivesTest.cpp
@@ -179,7 +179,7 @@
 // and there is no assert on input data in Debug mode.
 static void test_issue1083() {
     SkDynamicMemoryWStream outStream;
-    sk_sp<SkDocument> doc(SkDocument::CreatePDF(&outStream));
+    sk_sp<SkDocument> doc(SkDocument::MakePDF(&outStream));
     SkCanvas* canvas = doc->beginPage(100.0f, 100.0f);
     SkPaint paint;
     paint.setTextEncoding(SkPaint::kGlyphID_TextEncoding);
@@ -408,7 +408,7 @@
 // CPU rasterization.
 DEF_TEST(PDFImageFilter, reporter) {
     SkDynamicMemoryWStream stream;
-    sk_sp<SkDocument> doc(SkDocument::CreatePDF(&stream));
+    sk_sp<SkDocument> doc(SkDocument::MakePDF(&stream));
     SkCanvas* canvas = doc->beginPage(100.0f, 100.0f);
 
     sk_sp<DummyImageFilter> filter(DummyImageFilter::Make());