Fix priority of which font encoding is used.

test/pdfs/issue3064.pdf.link

@@ -0,0 +1,2 @@
+https://bugzilla.mozilla.org/attachment.cgi?id=733257
+

test/test_manifest.json

@@ -1013,6 +1013,14 @@
       "type": "eq",
       "about": "Has a 4 bit per component image with mask and decode."
     },
+    {  "id": "issue3064",
+      "file": "pdfs/issue3064.pdf",
+      "md5": "0307415b7d69b13acaf8bd4285d9544b",
+      "rounds": 1,
+      "link": true,
+      "type": "eq",
+      "about": "True type font with encoding dict with no base encoding but with differences."
+    },
     {  "id": "p020121130574743273239",
       "file": "pdfs/P020121130574743273239.pdf",
       "md5": "271b65885d42d174cbc597ca89becb1a",

test/unit/font_spec.js

@@ -383,7 +383,7 @@ describe('font', function() {
         'dup 33 /arrowright put\n' +
         'readonly def\n');
       var parser = new Type1Parser(stream);
-      var props = {};
+      var props = { overridableEncoding: true };
       var program = parser.extractFontHeader(props);
       expect(props.baseEncoding[33]).toEqual('arrowright');
     });