Don't log error from metricsPrivate API when GetVariationParams fails to find a

chrome/test/data/extensions/api_test/metrics/test.js

Index: chrome/test/data/extensions/api_test/metrics/test.js
diff --git a/chrome/test/data/extensions/api_test/metrics/test.js b/chrome/test/data/extensions/api_test/metrics/test.js
index 77e84b29969d166926c248231d07db8685342308..4f2b264d8b73df9e7109fef66bf011fe696c9ff2 100644
--- a/chrome/test/data/extensions/api_test/metrics/test.js
+++ b/chrome/test/data/extensions/api_test/metrics/test.js
@@ -90,8 +90,7 @@ chrome.test.runTests([
   function getVariationParams1() {
     chrome.metricsPrivate.getVariationParams(
         'apitestfieldtrial1', function(params) {
-      chrome.test.assertEq('Variation parameters are unavailable.',
-                           chrome.runtime.lastError.message);
+      chrome.test.assertEq(undefined, chrome.runtime.lastError);

[not at google - send to devlin, 2014/05/07 15:04:04]

Now's use of this function and the test disagree.

       chrome.test.assertEq(undefined, params);
       chrome.test.succeed();
     });