[Extensions Bindings] Support chrome.extension.lastError

chrome/test/data/extensions/api_test/native_bindings/extension/background.js

Index: chrome/test/data/extensions/api_test/native_bindings/extension/background.js
diff --git a/chrome/test/data/extensions/api_test/native_bindings/extension/background.js b/chrome/test/data/extensions/api_test/native_bindings/extension/background.js
index 0b6fc9ddd9851573f0b8b5a99600f258d3e810c7..560cecfe0d80be2ea9a946a7f543559e3180969d 100644
--- a/chrome/test/data/extensions/api_test/native_bindings/extension/background.js
+++ b/chrome/test/data/extensions/api_test/native_bindings/extension/background.js
@@ -124,7 +124,11 @@ var tests = [
   },
   function testLastError() {
     chrome.runtime.setUninstallURL('chrome://newtab', function() {
-      chrome.test.assertLastError('Invalid URL: "chrome://newtab".');
+      var expectedError = 'Invalid URL: "chrome://newtab".';
+      chrome.test.assertLastError(expectedError);
+      // Explicitly also test the old extension.lastError property.
+      chrome.test.assertTrue(!!chrome.extension.lastError);
+      chrome.test.assertEq(expectedError, chrome.extension.lastError.message);
       chrome.test.succeed();
     });
   },