Plumb file system permission into WebviewGuest.

chrome/browser/guest_view/guest_view.h

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef CHROME_BROWSER_GUEST_VIEW_GUEST_VIEW_H_
 #define CHROME_BROWSER_GUEST_VIEW_GUEST_VIEW_H_
 
 #include "chrome/browser/guest_view/guest_view_base.h"
+#include "content/public/browser/render_frame_host.h"
 
 template <typename T>
 class GuestView : public GuestViewBase {
  public:
   static T* From(int embedder_process_id, int guest_instance_id) {
     GuestViewBase* guest =
         GuestViewBase::From(embedder_process_id, guest_instance_id);
     if (!guest)
       return NULL;
     return guest->As<T>();
   }
 
   static T* FromWebContents(content::WebContents* contents) {
     GuestViewBase* guest = GuestViewBase::FromWebContents(contents);
     return guest ? guest->As<T>() : NULL;
   }
 
+  static T* FromFrameID(int render_process_id, int render_frame_id) {
+    content::RenderFrameHost* render_frame_host =
+        content::RenderFrameHost::FromID(render_process_id, render_frame_id);
+    if (!render_frame_host) {
+      return NULL;
+    }
+    content::WebContents* web_contents =
+        content::WebContents::FromRenderFrameHost(render_frame_host);
+    return FromWebContents(web_contents);
+  }
+
   T* GetOpener() const {
     GuestViewBase* guest = GuestViewBase::GetOpener();
     if (!guest)
       return NULL;
     return guest->As<T>();
   }
 
   void SetOpener(T* opener) {
     GuestViewBase::SetOpener(opener);
   }
 
   // GuestViewBase implementation.
   virtual const char* GetViewType() const OVERRIDE {
     return T::Type;
   }
 
  protected:
   GuestView(int guest_instance_id,
             content::WebContents* guest_web_contents,
             const std::string& embedder_extension_id)
       : GuestViewBase(guest_instance_id,
                       guest_web_contents,
                       embedder_extension_id) {}
 
  private:
   DISALLOW_COPY_AND_ASSIGN(GuestView);
 };
 
 #endif  // CHROME_BROWSER_GUEST_VIEW_GUEST_VIEW_H_