Add missing b2g snippet.

web/viewer-snippet-b2g.html

@@ -0,0 +1,9 @@
+<!-- This snippet is used in b2g, see Makefile -->
+<link rel="resource" type="application/l10n" href="locale.properties"/>
+<script type="text/javascript" src="l10n.js"></script>
+<script type="text/javascript" src="../build/pdf.js"></script>
+<script type="text/javascript">
+  // This specifies the location of the pdf.js file.
+  PDFJS.workerSrc = "../build/pdf.js";
+  PDFJS.disableTextLayer = true;
+</script>