[ios] Update non-native NTP for ios/web changes.

Hide the error page that now shows for the NTP, Ignore |success|
in -didLoadPageWithSuccess (as it's been meaningless for the NTP
forever), and move NewTabPageTabHelper to activate on
DidFinishNavigation as the NTP now loads asynchronously.

Bug: 826369
Change-Id: I8899668daca1f7862a8d6c234d1ad6f3aa963ca0
Reviewed-on: https://chromium-review.googlesource.com/c/1298181Reviewed-by: Eugene But <eugenebut@chromium.org>
Reviewed-by: Gauthier Ambard <gambard@chromium.org>
Commit-Queue: Justin Cohen <justincohen@chromium.org>
Cr-Commit-Position: refs/heads/master@{#602881}

ios/chrome/browser/ntp/new_tab_page_tab_helper.h

@@ -37,8 +37,8 @@ class NewTabPageTabHelper : public web::WebStateObserver,
 
   // web::WebStateObserver overrides:
   void WebStateDestroyed(web::WebState* web_state) override;
-  void DidStartNavigation(web::WebState* web_state,
-                          web::NavigationContext* navigation_context) override;
+  void DidFinishNavigation(web::WebState* web_state,
+                           web::NavigationContext* navigation_context) override;
 
   // Enable or disable the tab helper.
   void SetActive(bool active);

ios/chrome/browser/ntp/new_tab_page_tab_helper.mm

@@ -66,7 +66,7 @@ void NewTabPageTabHelper::WebStateDestroyed(web::WebState* web_state) {
   SetActive(false);
 }
 
-void NewTabPageTabHelper::DidStartNavigation(
+void NewTabPageTabHelper::DidFinishNavigation(
     web::WebState* web_state,
     web::NavigationContext* navigation_context) {
   if (navigation_context->IsSameDocument()) {

ios/chrome/browser/ntp/new_tab_page_tab_helper_unittest.mm

@@ -118,19 +118,19 @@ TEST_F(NewTabPageTabHelperTest, TestToggleToAndFromNTP) {
   GURL url(kChromeUINewTabURL);
   web::FakeNavigationContext context;
   context.SetUrl(url);
-  test_web_state_.OnNavigationStarted(&context);
+  test_web_state_.OnNavigationFinished(&context);
   EXPECT_TRUE(tab_helper()->IsActive());
 
   GURL not_ntp_url(kTestURL);
   context.SetUrl(not_ntp_url);
-  test_web_state_.OnNavigationStarted(&context);
+  test_web_state_.OnNavigationFinished(&context);
   EXPECT_FALSE(tab_helper()->IsActive());
 
   context.SetUrl(url);
-  test_web_state_.OnNavigationStarted(&context);
+  test_web_state_.OnNavigationFinished(&context);
   EXPECT_TRUE(tab_helper()->IsActive());
 
   context.SetUrl(not_ntp_url);
-  test_web_state_.OnNavigationStarted(&context);
+  test_web_state_.OnNavigationFinished(&context);
   EXPECT_FALSE(tab_helper()->IsActive());
 }

ios/chrome/browser/ui/content_suggestions/ntp_home_mediator.mm

@@ -186,9 +186,6 @@ const char kNTPHelpURL[] =
 
 - (void)webState:(web::WebState*)webState didLoadPageWithSuccess:(BOOL)success {
   DCHECK_EQ(_webState, webState);
-  if (!success)
-    return;
-
   [self setContentOffsetForWebState:webState];
 }
 

ios/chrome/browser/web/chrome_web_client.mm

@@ -211,6 +211,15 @@ void ChromeWebClient::PrepareErrorPage(NSError* error,
                                        bool is_off_the_record,
                                        NSString** error_html) {
   DCHECK(error);
+
+  // Return an empty page for the NTP.
+  NSString* url_spec = error.userInfo[NSURLErrorFailingURLStringErrorKey];
+  GURL url(base::SysNSStringToUTF16(url_spec));
+  if (url.GetOrigin() == kChromeUINewTabURL) {
+    *error_html = @"";
+    return;
+  }
+
   *error_html = GetErrorPage(error, is_post, is_off_the_record);
 }
 

ios/chrome/browser/web/chrome_web_client_unittest.mm

@@ -14,6 +14,7 @@
 #include "base/test/scoped_feature_list.h"
 #include "base/test/scoped_task_environment.h"
 #include "ios/chrome/browser/browser_state/test_chrome_browser_state.h"
+#include "ios/chrome/browser/chrome_url_constants.h"
 #include "ios/chrome/browser/passwords/credential_manager_features.h"
 #import "ios/chrome/browser/web/error_page_util.h"
 #import "ios/web/public/test/error_test_util.h"
@@ -220,3 +221,20 @@ TEST_F(ChromeWebClientTest, PrepareErrorPagePostOtr) {
   EXPECT_NSEQ(GetErrorPage(error, /*is_post=*/true, /*is_off_the_record=*/true),
               page);
 }
+
+// Tests PrepareErrorPage wth NTP and an empty string.
+TEST_F(ChromeWebClientTest, PrepareErrorPageNTP) {
+  ChromeWebClient web_client;
+  NSString* ntp_url = base::SysUTF8ToNSString(kChromeUINewTabURL);
+  NSDictionary* info = @{
+    NSURLErrorFailingURLStringErrorKey : ntp_url,
+  };
+  NSError* error = web::testing::CreateTestNetError([NSError
+      errorWithDomain:NSURLErrorDomain
+                 code:NSURLErrorNetworkConnectionLost
+             userInfo:info]);
+  NSString* page = nil;
+  web_client.PrepareErrorPage(error, /*is_post=*/false,
+                              /*is_off_the_record=*/false, &page);
+  EXPECT_NSEQ(@"", page);
+}