Track where WebContents are created in order to better understand issue.

ui/views/controls/webview/webview.cc

Index: ui/views/controls/webview/webview.cc
diff --git a/ui/views/controls/webview/webview.cc b/ui/views/controls/webview/webview.cc
index 8e6465ea757efa96e7de1c4c11bddabc540418d6..a09dc5c3612617fb7e72e3a4e2de81a20e2bf35e 100644
--- a/ui/views/controls/webview/webview.cc
+++ b/ui/views/controls/webview/webview.cc
@@ -11,6 +11,7 @@
 #include "content/public/browser/render_view_host.h"
 #include "content/public/browser/render_widget_host_view.h"
 #include "content/public/browser/web_contents.h"
+#include "content/public/browser/web_contents_source.h"
 #include "ipc/ipc_message.h"
 #include "ui/accessibility/ax_enums.h"
 #include "ui/accessibility/ax_view_state.h"
@@ -390,7 +391,10 @@ content::WebContents* WebView::CreateWebContents(
   if (!contents) {
     content::WebContents::CreateParams create_params(
         browser_context, NULL);
-    return content::WebContents::Create(create_params);
+    content::WebContents* web_contents =
+        content::WebContents::Create(create_params);
+    WebContentsSource::CreateForWebContentsAndLocation(web_contents, FROM_HERE);
+    return web_contents;
   }
 
   return contents;