Enable the no-unused-vars ESLint rule

Please see http://eslint.org/docs/rules/no-unused-vars; note that this patch purposely uses the same rule options as in `mozilla-central`, such that it fixes part of issue 7957.

It wasn't, in my opinion, entirely straightforward to enable this rule compared to the already existing rules. In many cases a `var descriptiveName = ...` format was used (more or less) to document the code, and I choose to place the old variable name in a trailing comment to not lose that information.

I welcome feedback on these changes, since it wasn't always entirely easy to know what changes made the most sense in every situation.

test/driver.js

@@ -673,3 +673,5 @@ var Driver = (function DriverClosure() {
 
   return Driver;
 })();
+
+exports.Driver = Driver;

test/font/fontutils.js

@@ -88,3 +88,7 @@ function verifyTtxOutput(output) {
     throw m[1];
   }
 }
+
+exports.decodeFontData = decodeFontData;
+exports.ttx = ttx;
+exports.verifyTtxOutput = verifyTtxOutput;

test/unit/cff_parser_spec.js

@@ -189,7 +189,7 @@ describe('CFFParser', function() {
   it('parses a CharString endchar with 4 args w/seac enabled', function() {
     var parser = new CFFParser(fontData, {},
                                /* seacAnalysisEnabled = */ true);
-    var cff = parser.parse();
+    parser.parse(); // cff
 
     var bytes = new Uint8Array([0, 1, // count
                                 1,  // offsetSize
@@ -211,7 +211,7 @@ describe('CFFParser', function() {
   it('parses a CharString endchar with 4 args w/seac disabled', function() {
     var parser = new CFFParser(fontData, {},
                                /* seacAnalysisEnabled = */ false);
-    var cff = parser.parse();
+    parser.parse(); // cff
 
     var bytes = new Uint8Array([0, 1, // count
                                 1,  // offsetSize

test/unit/jasmine-boot.js

@@ -40,8 +40,6 @@
 
 'use strict';
 
-var pdfjsLibs;
-
 function initializePDFJS(callback) {
   require.config({paths: {'pdfjs': '../../src', 'pdfjs-web': '../../web',
                  'pdfjs-test': '..'}});

test/unit/network_spec.js

@@ -63,7 +63,7 @@ describe('network', function() {
       });
     };
 
-    var readPromise = read();
+    var readPromise = Promise.all([read(), promise]);
 
     readPromise.then(function (page) {
       expect(len).toEqual(pdf1Length);
@@ -117,12 +117,13 @@ describe('network', function() {
       });
     };
 
-    var readPromise = read();
+    var readPromise = Promise.all([read(), promise]);
 
     readPromise.then(function () {
       expect(len).toEqual(pdf2Length);
       expect(count).toBeGreaterThan(1);
       expect(isStreamingSupported).toEqual(true);
+      expect(isRangeSupported).toEqual(true);
       done();
     }).catch(function (reason) {
       done.fail(reason);
@@ -179,6 +180,7 @@ describe('network', function() {
     readPromises.then(function () {
       expect(result1.value).toEqual(rangeSize);
       expect(result2.value).toEqual(tailSize);
+      expect(isStreamingSupported).toEqual(false);
       expect(isRangeSupported).toEqual(true);
       expect(fullReaderCancelled).toEqual(true);
       done();

test/unit/testreporter.js

@@ -74,3 +74,5 @@ var TestReporter = function(browser, appPath) {
     setTimeout(sendQuitRequest, 500);
   };
 };
+
+exports.TestReporter = TestReporter;