Avoid crash in ContentSettingsObserver::GetOriginOrURL with top remote frames.

chrome/renderer/content_settings_observer.cc

Index: chrome/renderer/content_settings_observer.cc
diff --git a/chrome/renderer/content_settings_observer.cc b/chrome/renderer/content_settings_observer.cc
index 8bd0430b15b7f9d5a016f7fbce3a8d4e4dc0da13..663288d26c8abdceb7043dc12f43b519d4c64e2d 100644
--- a/chrome/renderer/content_settings_observer.cc
+++ b/chrome/renderer/content_settings_observer.cc
@@ -49,8 +49,8 @@ GURL GetOriginOrURL(const WebFrame* frame) {
   // document URL as the primary URL in those cases.
   // TODO(alexmos): This is broken for --site-per-process, since top() can be a
   // WebRemoteFrame which does not have a document(), and the WebRemoteFrame's
-  // URL is not replicated.
-  if (top_origin == "null")
+  // URL is not replicated.  See https://crbug.com/628759.
+  if (top_origin == "null" && frame->top()->isWebLocalFrame())
     return frame->top()->document().url();
   return blink::WebStringToGURL(top_origin);
 }