PlzNavigate: Show error pages when the navigation failed before commit

content/public/test/test_navigation_observer.cc

Index: content/public/test/test_navigation_observer.cc
diff --git a/content/public/test/test_navigation_observer.cc b/content/public/test/test_navigation_observer.cc
index 7c2d0281a59b552e57522f317a001b445940ca53..5e16f35ea087a97391f139e2b3a733d6d1fc2f4d 100644
--- a/content/public/test/test_navigation_observer.cc
+++ b/content/public/test/test_navigation_observer.cc
@@ -76,31 +76,29 @@ class TestNavigationObserver::TestWebContentsObserver
   DISALLOW_COPY_AND_ASSIGN(TestWebContentsObserver);
 };
 
-TestNavigationObserver::TestNavigationObserver(
-    WebContents* web_contents,
-    int number_of_navigations)
+TestNavigationObserver::TestNavigationObserver(WebContents* web_contents,
+                                               int number_of_navigations)
     : navigation_started_(false),
       navigations_completed_(0),
       number_of_navigations_(number_of_navigations),
+      navigations_failed_(0),
       message_loop_runner_(new MessageLoopRunner),
       web_contents_created_callback_(
-          base::Bind(
-              &TestNavigationObserver::OnWebContentsCreated,
-              base::Unretained(this))) {
+          base::Bind(&TestNavigationObserver::OnWebContentsCreated,
+                     base::Unretained(this))) {
   if (web_contents)
     RegisterAsObserver(web_contents);
 }
 
-TestNavigationObserver::TestNavigationObserver(
-    WebContents* web_contents)
+TestNavigationObserver::TestNavigationObserver(WebContents* web_contents)
     : navigation_started_(false),
       navigations_completed_(0),
       number_of_navigations_(1),
+      navigations_failed_(0),
       message_loop_runner_(new MessageLoopRunner),
       web_contents_created_callback_(
-          base::Bind(
-              &TestNavigationObserver::OnWebContentsCreated,
-              base::Unretained(this))) {
+          base::Bind(&TestNavigationObserver::OnWebContentsCreated,
+                     base::Unretained(this))) {
   if (web_contents)
     RegisterAsObserver(web_contents);
 }
@@ -186,6 +184,7 @@ void TestNavigationObserver::OnDidFailProvisionalLoad(
     const base::string16& error_description) {
   last_navigation_url_ = validated_url;
   last_navigation_succeeded_ = false;
+  ++navigations_failed_;
 }
 
 void TestNavigationObserver::OnDidCommitProvisionalLoadForFrame(