Instantiate PageLoadTrackers for prerenders

chrome/browser/page_load_metrics/metrics_web_contents_observer_unittest.cc

Index: chrome/browser/page_load_metrics/metrics_web_contents_observer_unittest.cc
diff --git a/chrome/browser/page_load_metrics/metrics_web_contents_observer_unittest.cc b/chrome/browser/page_load_metrics/metrics_web_contents_observer_unittest.cc
index 272e405985903cc32f025bd00ce61c0ed7232b14..91468dbfcf7fa03f0bc3629beb02a9290dfc2045 100644
--- a/chrome/browser/page_load_metrics/metrics_web_contents_observer_unittest.cc
+++ b/chrome/browser/page_load_metrics/metrics_web_contents_observer_unittest.cc
@@ -277,14 +277,14 @@ TEST_F(MetricsWebContentsObserverTest, DontLogPrerender) {
   content::WebContentsTester* web_contents_tester =
       content::WebContentsTester::For(web_contents());
   embedder_interface_->set_is_prerendering(true);
+  observer_->WasHidden();

[Charlie Harrison, 2016/09/22 14:51:24]

Does removing this cause the test to fail?

[Bryan McQuade, 2016/09/22 15:14:37]

I added a DCHECK(!started_in_foreground_); for the prerender case, to make sure
that bit gets set sanely for prerenders. As a result, I had to change this as
well.

[Charlie Harrison, 2016/09/22 15:16:31]

Ahh, right! LGTM that's what I want.

 
   web_contents_tester->NavigateAndCommit(GURL(kDefaultTestUrl));
   SimulateTimingUpdate(timing);
   web_contents_tester->NavigateAndCommit(GURL(kDefaultTestUrl2));
   ASSERT_EQ(0, CountUpdatedTimingReported());
   ASSERT_EQ(0, CountCompleteTimingReported());
-  CheckErrorEvent(ERR_IPC_WITH_NO_RELEVANT_LOAD, 1);
-  CheckTotalErrorEvents();
+  CheckNoErrorEvents();
 }
 
 TEST_F(MetricsWebContentsObserverTest, DontLogNewTabPage) {