Gracefully handle didCommitNavigation: call after didFinishNavigation:

ios/web/web_state/ui/crw_wk_navigation_states.mm

Index: ios/web/web_state/ui/crw_wk_navigation_states.mm
diff --git a/ios/web/web_state/ui/crw_wk_navigation_states.mm b/ios/web/web_state/ui/crw_wk_navigation_states.mm
index 235562e4f5ebbeb90f9dc63d04a1d92b996bebd5..13d852a80d28029f03f7ed5e62987e71f4885686 100644
--- a/ios/web/web_state/ui/crw_wk_navigation_states.mm
+++ b/ios/web/web_state/ui/crw_wk_navigation_states.mm
@@ -122,14 +122,22 @@
         [[CRWWKNavigationsStateRecord alloc] initWithState:state
                                                      index:++_lastStateIndex];
   } else {
-    DCHECK(
-        record.state < state ||
-        (record.state == state && state == web::WKNavigationState::REDIRECTED));
+    DCHECK(record.state < state ||
+           (record.state == state &&
+            state == web::WKNavigationState::REDIRECTED) ||
+           (record.state == web::WKNavigationState::FINISHED &&
+            state == web::WKNavigationState::COMMITTED));

[kkhorimoto, 2017/06/22 00:49:02]

Can you add some comments for this DCHECK explaining why the latter two
exceptions are there?

[Eugene But (OOO till 7-30), 2017/06/22 01:58:06]

Done.

     record.state = state;
   }
   [_records setObject:record forKey:key];
 }
 
+- (web::WKNavigationState)stateForNavigation:(WKNavigation*)navigation {
+  id key = [self keyForNavigation:navigation];
+  CRWWKNavigationsStateRecord* record = [_records objectForKey:key];
+  return record ? record.state : web::WKNavigationState::NONE;
+}
+
 - (void)removeNavigation:(WKNavigation*)navigation {
   id key = [self keyForNavigation:navigation];
   DCHECK([_records objectForKey:key]);