Only disallow top-level navigations in platform apps

content/renderer/render_view_impl.h

Index: content/renderer/render_view_impl.h
diff --git a/content/renderer/render_view_impl.h b/content/renderer/render_view_impl.h
index 64085806118d287c739193f6de4aa3a704a384a5..f29024bf1f4c61e92fffd84df2f19bbb28452e9e 100644
--- a/content/renderer/render_view_impl.h
+++ b/content/renderer/render_view_impl.h
@@ -992,7 +992,13 @@ class RenderViewImpl : public RenderWidget,
   // Returns false unless this is a top-level navigation that crosses origins.
   bool IsNonLocalTopLevelNavigation(const GURL& url,
                                     WebKit::WebFrame* frame,
-                                    WebKit::WebNavigationType type);
+                                    WebKit::WebNavigationType type) const;
+
+  // Returns true if |frame| is the top frame, or if the URL being loaded is
+  // from a different origin than the top frame's (except for data: URLs, which
+  // are not considered remote).
+  bool IsRemoteOrTopLevelNavigation(const GURL& url,
+                                    WebKit::WebFrame* frame) const;
 
   bool MaybeLoadAlternateErrorPage(WebKit::WebFrame* frame,
                                    const WebKit::WebURLError& error,