Move blocking of top-level navigations to nested URLs with extension origins from non-extension pro…

content/public/browser/navigation_handle.h

Index: content/public/browser/navigation_handle.h
diff --git a/content/public/browser/navigation_handle.h b/content/public/browser/navigation_handle.h
index 8770777171da92bf15cb92d1d4a0117004c22115..4c0694eda5d3d96986c554f976b7aaeaa021ac2c 100644
--- a/content/public/browser/navigation_handle.h
+++ b/content/public/browser/navigation_handle.h
@@ -23,6 +23,7 @@ namespace content {
 class NavigationData;
 class NavigationThrottle;
 class RenderFrameHost;
+class SiteInstance;
 class WebContents;
 
 // A NavigationHandle tracks information related to a single navigation.
@@ -48,6 +49,11 @@ class CONTENT_EXPORT NavigationHandle {
   // virtual URL is prefixed with "view-source:".
   virtual const GURL& GetURL() = 0;
 
+  // Returns the SiteInstance that started the request.
+  // If a frame in SiteInstance A navigates a frame in SiteInstance B to a URL
+  // in SiteInstance C, then this returns B.
+  virtual SiteInstance* GetStartingSiteInstance() = 0;
+
   // Whether the navigation is taking place in the main frame or in a subframe.
   // This remains constant over the navigation lifetime.
   virtual bool IsInMainFrame() = 0;