[Nav Experiment] Fix offline reading list for WKBasedNavigationManager.

When handling a no-Internet-connection error, WKBasedNavigationManager
incorrectly triggers WebState::OnPageLoaded with load completion status
SUCCESS when the native error view is loaded. This prevented
ReadingListWebStateObserver from triggering and loading offline content
and is now fixed.

Since offline reading list is essentially another type of native error,
we must not update the navigation item's |errorRetryState| when loading
a chrome://offline URL. This is so that a reload of the page will retry
loading the original URL. This is fixed by only updating the error retry
state machine when the URL is a web URL. This is OK because app-specific
URL should never fail to load.

Bug: 819805
Cq-Include-Trybots: master.tryserver.chromium.mac:ios-simulator-cronet;master.tryserver.chromium.mac:ios-simulator-full-configs
Change-Id: I870ef99522ba6f5aeb4d37c58289155aa8cb79c9
Reviewed-on: https://chromium-review.googlesource.com/996434
Commit-Queue: Danyao Wang <danyao@chromium.org>
Reviewed-by: Eugene But <eugenebut@chromium.org>
Cr-Commit-Position: refs/heads/master@{#548454}

ios/web/web_state/ui/crw_web_controller.mm

@@ -2012,7 +2012,11 @@ registerLoadRequestForURL:(const GURL&)requestURL
   // nothing if the document has already loaded.
   if (_loadPhase == web::PAGE_LOADED)
     return;
-  [self loadCompleteWithSuccess:YES forNavigation:navigation];
+
+  web::NavigationContextImpl* context =
+      [_navigationStates contextForNavigation:navigation];
+  BOOL success = !context || !context->GetError();
+  [self loadCompleteWithSuccess:success forNavigation:navigation];
 }
 
 - (void)loadCompleteWithSuccess:(BOOL)loadSuccess
@@ -4697,7 +4701,7 @@ registerLoadRequestForURL:(const GURL&)requestURL
         // of session restoration. It is now safe to update the navigation
         // item URL to the original app-specific URL.
         item->SetURL(originalURL);
-      } else if (item->GetURL() != originalURL) {
+      } else if (item->GetVirtualURL() != originalURL) {
         // The |didFinishNavigation| callback can arrive after another
         // navigation has started. Abort in this case.
         return;
@@ -4731,29 +4735,34 @@ registerLoadRequestForURL:(const GURL&)requestURL
       }
     }
 
-    // Handle state transitions for retrying a previously failed navigation.
-    switch (errorRetryState) {
-      case web::ErrorRetryState::kDisplayingErrorForFailedNavigation:
-        DCHECK(context->GetPageTransition() & ui::PAGE_TRANSITION_FORWARD_BACK);
-        if (item->GetURL() == webViewURL) {
-          // Shortcut: if WebView already has the original URL (can happen when
-          // WebKit renders page from cache after after repeated back/forward
-          // navigations), skip kNavigatingToFailedNavigationItem state and just
-          // reload the page.
+    // Handle state transitions for retrying a previously failed navigation to a
+    // web URL. App-specific URLs should never fail to load so should not change
+    // the error retry state.
+    if (!web::GetWebClient()->IsAppSpecificURL(item->GetURL())) {
+      switch (errorRetryState) {
+        case web::ErrorRetryState::kDisplayingErrorForFailedNavigation:
+          DCHECK(context->GetPageTransition() &
+                 ui::PAGE_TRANSITION_FORWARD_BACK);
+          if (item->GetURL() == webViewURL) {
+            // Shortcut: if WebView already has the original URL (can happen
+            // when WebKit renders page from cache after after repeated
+            // back/forward navigations), skip kNavigatingToFailedNavigationItem
+            // state and just reload the page.
+            [self handleRetryFailedNavigationItem:item];
+          } else {
+            [self handleNavigationToFailedNavigationItem:item];
+          }
+          break;
+        case web::ErrorRetryState::kNavigatingToFailedNavigationItem:
           [self handleRetryFailedNavigationItem:item];
-        } else {
-          [self handleNavigationToFailedNavigationItem:item];
-        }
-        break;
-      case web::ErrorRetryState::kNavigatingToFailedNavigationItem:
-        [self handleRetryFailedNavigationItem:item];
-        break;
-      case web::ErrorRetryState::kRetryFailedNavigationItem:
-        item->SetErrorRetryState(web::ErrorRetryState::kNoNavigationError);
-        break;
-      case web::ErrorRetryState::kNoNavigationError:
-      case web::ErrorRetryState::kReadyToDisplayErrorForFailedNavigation:
-        break;
+          break;
+        case web::ErrorRetryState::kRetryFailedNavigationItem:
+          item->SetErrorRetryState(web::ErrorRetryState::kNoNavigationError);
+          break;
+        case web::ErrorRetryState::kNoNavigationError:
+        case web::ErrorRetryState::kReadyToDisplayErrorForFailedNavigation:
+          break;
+      }
     }
   }