Better distinguish didFinishLoad and didStopLoading

chrome/browser/extensions/api/web_navigation/web_navigation_api.cc

Index: chrome/browser/extensions/api/web_navigation/web_navigation_api.cc
diff --git a/chrome/browser/extensions/api/web_navigation/web_navigation_api.cc b/chrome/browser/extensions/api/web_navigation/web_navigation_api.cc
index 2e8522fb0e484f0f6572bcc9d02a8bc66339bad1..52462b3b7b5d1f41b1d9bdb337e7a9ae25594068 100644
--- a/chrome/browser/extensions/api/web_navigation/web_navigation_api.cc
+++ b/chrome/browser/extensions/api/web_navigation/web_navigation_api.cc
@@ -398,12 +398,16 @@ void WebNavigationTabObserver::DidFinishLoad(
   navigation_state_.SetNavigationCompleted(render_frame_host);
   if (!navigation_state_.CanSendEvents(render_frame_host))
     return;
-  DCHECK(navigation_state_.GetUrl(render_frame_host) == validated_url ||
-         (navigation_state_.GetUrl(render_frame_host) ==
-              GURL(content::kAboutSrcDocURL) &&
-          validated_url == GURL(url::kAboutBlankURL)))
-      << "validated URL is " << validated_url << " but we expected "
-      << navigation_state_.GetUrl(render_frame_host);
+
+  // A new navigation might have started before the old one completed.
+  // Ignore the old navigation completion in that case.
+  // srcdoc iframes will report a url of about:blank, still let it through.
+  if (navigation_state_.GetUrl(render_frame_host) != validated_url &&
+      (navigation_state_.GetUrl(render_frame_host) !=
+           GURL(content::kAboutSrcDocURL) ||
+       validated_url != GURL(url::kAboutBlankURL))) {
+    return;

[nasko, 2015/10/12 23:48:24]

Does your change imply that a DidFailLoad will be called if we start a new
provisional load before DidFinishLoad is called? Or would we call DidFailLoad
only when the provisional load is ready for commit?
I'm trying to understand the exact sequence of events that was hitting this
CHECK and how it will behave with your changes.

+  }
 
   // The load might already have finished by the time we finished parsing. For
   // compatibility reasons, we artifically delay the load completed signal until