Fire window.onerror for uncaught IndexedDB errors

LayoutTests/resources/js-test.js

 // svg/dynamic-updates tests set enablePixelTesting=true, as we want to dump text + pixel results
 if (self.testRunner) {
     if (self.enablePixelTesting)
         testRunner.dumpAsTextWithPixelResults();
     else
         testRunner.dumpAsText();
 }
 
 var description, debug, successfullyParsed;
 
-var expectingError; // set by shouldHaveError()
+var expectingError; // set by expectError()
 var expectedErrorMessage; // set by onerror when expectingError is true
 var unexpectedErrorMessage; // set by onerror when expectingError is not true
 
 (function() {
 
     function getOrCreate(id, tagName)
     {
         var element = document.getElementById(id);
         if (element)
             return element;
@@ skipping 72 matching lines @@
         window.addEventListener('DOMContentLoaded', handleTestFinished, false);
         insertStyleSheet();
     }
 
     if (!self.isOnErrorTest) {
         self.onerror = function(message)
         {
             if (self.expectingError) {
                 self.expectedErrorMessage = message;
                 self.expectingError = false;
-                return;
+                // Consume expected error in worker, so window doesn't fail the test.
+                return isWorker();
             }
             self.unexpectedErrorMessage = message;
             if (self.jsTestIsAsync) {
                 self.testFailed("Unexpected error: " + message);
                 finishJSTest();
             }
         };
     }
 })();
 
@@ skipping 509 matching lines @@
 
         testPassed(a + " is equivalent to Date.now().");
         return;
     }
     testFailed(a + " cannot be tested against the current time. The clock is going backwards too often.");
 }
 
 function expectError()
 {
     if (expectingError) {
-        testFailed("shouldHaveError() called twice before an error occurred!");
+        testFailed("expectError() called twice before an error occurred!");
     }
     expectingError = true;
 }
 
 function shouldHaveHadError(message)
 {
     if (expectingError) {
         testFailed("No error thrown between expectError() and shouldHaveHadError()");
         return;
     }
@@ skipping 140 matching lines @@
     testPassed = function(msg) {
         workerPort.postMessage('PASS:' + msg);
     };
     finishJSTest = function() {
         workerPort.postMessage('DONE:');
     };
     debug = function(msg) {
         workerPort.postMessage(msg);
     };
 }