Modify pdf_scripting_api.js to support postMessage using BrowserPlugin

chrome/test/data/pdf/basic_plugin_test.js

Index: chrome/test/data/pdf/basic_plugin_test.js
diff --git a/chrome/test/data/pdf/basic_plugin_test.js b/chrome/test/data/pdf/basic_plugin_test.js
index 3fdc90878d57b661cf14714e4c407a5741bab4db..1e0d7e62902f8e7dfedbaac9c79cd63b9004198a 100644
--- a/chrome/test/data/pdf/basic_plugin_test.js
+++ b/chrome/test/data/pdf/basic_plugin_test.js
@@ -21,8 +21,7 @@ var tests = [
   },
 
   function testAccessibility() {
-    var client = new PDFScriptingAPI(window, window.location.origin);
-    client.setDestinationWindow(window);
+    var client = new PDFScriptingAPI(window, window);
     client.getAccessibilityJSON(chrome.test.callbackPass(function(json) {
       var dict = JSON.parse(json);
       chrome.test.assertEq(true, dict.copyable);
@@ -32,8 +31,7 @@ var tests = [
   },
 
   function testAccessibilityWithPage() {
-    var client = new PDFScriptingAPI(window, window.location.origin);
-    client.setDestinationWindow(window);
+    var client = new PDFScriptingAPI(window, window);
     client.getAccessibilityJSON(chrome.test.callbackPass(function(json) {
       var dict = JSON.parse(json);
       chrome.test.assertEq(612, dict.width);
@@ -50,10 +48,7 @@ var tests = [
   }
 ];
 
-if (viewer.loaded) {
+var client = new PDFScriptingAPI(window, window);
+client.setLoadCallback(function() {
   chrome.test.runTests(tests);
-} else {
-  window.addEventListener('pdfload', function() {
-    chrome.test.runTests(tests);
-  });
-}
+});