Implement FPDF_VIEWERREF_GetName() API.
This is a generic API function to retrieve any viewer preference of type
name.
BUG=pdfium:414
Review-Url: https://codereview.chromium.org/2475923003
diff --git a/testing/resources/viewer_ref.in b/testing/resources/viewer_ref.in
new file mode 100644
index 0000000..62ae372
--- /dev/null
+++ b/testing/resources/viewer_ref.in
@@ -0,0 +1,57 @@
+{{header}}
+{{object 1 0}} <<
+ /Type /Catalog
+ /Pages 2 0 R
+ /ViewerPreferences <<
+ /Foo /foo
+ /HideToolbar true
+ /Direction /R2L
+ /ViewArea /CropBox
+ /NumCopies 5
+ >>
+>>
+endobj
+{{object 2 0}} <<
+ /Type /Pages
+ /Count 1
+ /Kids [
+ 3 0 R
+ ]
+>>
+endobj
+% Page number 0.
+{{object 3 0}} <<
+ /Type /Page
+ /Parent 2 0 R
+ /Resources <<
+ /Font <</F1 15 0 R>>
+ >>
+ /Contents [21 0 R]
+ /MediaBox [0 0 612 792]
+>>
+endobj
+% Font resource.
+{{object 15 0}} <<
+ /Type /Font
+ /Subtype /Type1
+ /BaseFont /Arial
+>>
+endobj
+% Content for page 0.
+{{object 21 0}} <<
+ /Length 0
+>>
+stream
+BT
+/F1 20 Tf
+100 600 TD (Page1)Tj
+ET
+endstream
+endobj
+{{xref}}
+trailer <<
+ /Size 6
+ /Root 1 0 R
+>>
+{{startxref}}
+%%EOF
