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..3d196e09b27fa34d7bf9add4e5958dbc4aed00e1 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 +398,15 @@ 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.
+  if (navigation_state_.GetUrl(render_frame_host) != validated_url &&

[dcheng, 2015/10/08 05:34:35]

This first check seems obviously related to the comment, but I'm having a hard
time understanding how the other two relate. Would it be possible to clarify the
comment here?

[Nate Chapin, 2015/10/08 21:03:59]

Done.

+      (navigation_state_.GetUrl(render_frame_host) !=
+           GURL(content::kAboutSrcDocURL) ||
+       validated_url != GURL(url::kAboutBlankURL))) {
+    return;
+  }
 
   // The load might already have finished by the time we finished parsing. For
   // compatibility reasons, we artifically delay the load completed signal until