…d pages

When using the PDF.js viewer extension for Chrome
(https://chrome.google.com/webstore/detail/pdf-viewer/oemmndcbldboiebfnladdacbdfmadadm)
PDF files will open in a URL with a chrome-extension:// scheme
which Chrome disallows content script injecton into.

Check the URL scheme before attempting to detect the content type
and assume HTML if not a supported scheme.

h/browser/chrome/lib/sidebar-injector.js

@@ -6,6 +6,7 @@ var messageTypes = require('./message-types');
var settings = require('./settings');
var util = require('./util');

var CONTENT_TYPE_HTML = 'HTML';
var CONTENT_TYPE_PDF = 'PDF';

// a function which is executed as a content script
@@ -97,6 +98,10 @@ function SidebarInjector(chromeTabs, dependencies) {
  }

  function detectTabContentType(tab) {
    if (!isSupportedURL(tab.url)) {
      return Promise.resolve(CONTENT_TYPE_HTML);
    }

    return executeScriptFn(tab.id, {
        code: toIIFEString(detectContentType)
      }).then(function (frameResults) {
@@ -113,9 +118,12 @@ function SidebarInjector(chromeTabs, dependencies) {
  }

  function isSupportedURL(url) {
    var SUPPORTED_PROTOCOLS = ['http:', 'https:', 'ftp:'];
    // Injection of content scripts is limited to a small number of protocols,
    // see https://developer.chrome.com/extensions/match_patterns
    var parsedURL = new URL(url);
    var SUPPORTED_PROTOCOLS = ['http:', 'https:', 'ftp:', 'file:'];
    return SUPPORTED_PROTOCOLS.some(function (protocol) {
      return url.indexOf(protocol) === 0;
      return parsedURL.protocol === protocol;
    });
  }