Remove useWorker variable and turn worker support whenever this is possible.

src/core.js

@@ -7,7 +7,6 @@ var globalScope = (typeof window === 'undefined') ? this : window;
 
 var ERRORS = 0, WARNINGS = 1, TODOS = 5;
 var verbosity = WARNINGS;
-var useWorker = false;
 
 // The global PDFJS object exposes the API
 // In production, it will be declared outside a global wrapper
@@ -470,8 +469,14 @@ var PDFDoc = (function pdfDoc() {
     this.objs = new PDFObjects();
 
     this.pageCache = [];
+    this.workerReadyPromise = new Promise('workerReady');
 
-    if (useWorker) {
+    // If worker support isn't disabled explicit and the browser has worker
+    // support, create a new web worker and test if it/the browser fullfills
+    // all requirements to run parts of pdf.js in a web worker.
+    // Right now, the requirement is, that an Uint8Array is still an Uint8Array
+    // as it arrives on the worker. Chrome added this with version 15.
+    if (!globalScope.PDFJS.disableWorker && typeof Worker !== 'undefined') {
       var workerSrc = PDFJS.workerSrc;
       if (typeof workerSrc === 'undefined') {
         throw 'No PDFJS.workerSrc specified';
@@ -479,26 +484,50 @@ var PDFDoc = (function pdfDoc() {
 
       var worker = new Worker(workerSrc);
 
+      var processorHandler = new MessageHandler('main', worker);
+
       // Tell the worker the file it was created from.
-      worker.postMessage({
+      processorHandler.send('workerSrc', workerSrc);
-        action: 'workerSrc',
+
-        data: workerSrc
+      processorHandler.on('test', function pdfDocTest(supportTypedArray) {
-      });
+        if (supportTypedArray) {
+          this.worker = worker;
+          this.setupProcessorHandler(processorHandler);
         } else {
+          this.setupFakeWorker();
+        }
+      }.bind(this));
+
+      var testObj = new Uint8Array(1);
+      processorHandler.send('test', testObj);
+    } else {
+      this.setupFakeWorker();
+    }
+
+    this.fontsLoading = {};
+  }
+
+  constructor.prototype = {
+    setupFakeWorker: function() {
       // If we don't use a worker, just post/sendMessage to the main thread.
-      var worker = {
+      var fakeWorker = {
         postMessage: function pdfDocPostMessage(obj) {
-          worker.onmessage({data: obj});
+          fakeWorker.onmessage({data: obj});
         },
         terminate: function pdfDocTerminate() {}
       };
-    }
-    this.worker = worker;
 
-    this.fontsLoading = {};
+      var processorHandler = new MessageHandler('main', fakeWorker);
+      this.setupProcessorHandler(processorHandler);
 
-    var processorHandler = this.processorHandler =
+      // If the main thread is our worker, setup the handling for the messages
-                                        new MessageHandler('main', worker);
+      // the main thread sends to it self.
+      WorkerProcessorHandler.setup(processorHandler);
+    },
+
+
+    setupProcessorHandler: function(processorHandler) {
+      this.processorHandler = processorHandler;
 
       processorHandler.on('page', function pdfDocPage(data) {
         var pageNum = data.pageNum;
@@ -564,20 +593,12 @@ var PDFDoc = (function pdfDoc() {
         }
       }.bind(this));
 
-    if (!useWorker) {
-      // If the main thread is our worker, setup the handling for the messages
-      // the main thread sends to it self.
-      WorkerProcessorHandler.setup(processorHandler);
-    }
-
-    this.workerReadyPromise = new Promise('workerReady');
       setTimeout(function pdfDocFontReadySetTimeout() {
         processorHandler.send('doc', this.data);
         this.workerReadyPromise.resolve(true);
       }.bind(this));
-  }
+    },
 
-  constructor.prototype = {
     get numPages() {
       return this.pdf.numPages;
     },

src/worker.js

@@ -47,6 +47,10 @@ var WorkerProcessorHandler = {
   setup: function wphSetup(handler) {
     var pdfDoc = null;
 
+    handler.on('test', function wphSetupTest(data) {
+      handler.send('test', data instanceof Uint8Array);
+    });
+
     handler.on('workerSrc', function wphSetupWorkerSrc(data) {
       // In development, the `workerSrc` message is handled in the
       // `worker_loader.js` file. In production the workerProcessHandler is