Fix copying from interstitial pages on OSX by going through the RenderWidgetHostDelegate.

content/browser/frame_host/interstitial_page_impl.h

 // Copyright 2013 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 CONTENT_BROWSER_FRAME_HOST_INTERSTITIAL_PAGE_IMPL_H_
 #define CONTENT_BROWSER_FRAME_HOST_INTERSTITIAL_PAGE_IMPL_H_
 
 #include "base/compiler_specific.h"
 #include "base/memory/scoped_ptr.h"
 #include "base/memory/weak_ptr.h"
@@ skipping 38 matching lines @@
     DONT_PROCEED_ACTION  // "Don't proceed" was selected.
   };
 
   InterstitialPageImpl(WebContents* web_contents,
                        RenderWidgetHostDelegate* render_widget_host_delegate,
                        bool new_navigation,
                        const GURL& url,
                        InterstitialPageDelegate* delegate);
   ~InterstitialPageImpl() override;
 
+  // RenderWidgetHostDelegate implementation:
+  void Undo() override;
+  void Redo() override;
+  void Cut() override;
+  void Copy() override;
+  void CopyToFindPboard() override;
+  void Paste() override;
+  void PasteAndMatchStyle() override;
+  void SelectAll() override;
+
   // InterstitialPage implementation:
   void Show() override;
   void Hide() override;
   void DontProceed() override;
   void Proceed() override;
   RenderFrameHost* GetMainFrame() const override;
   InterstitialPageDelegate* GetDelegateForTesting() override;
   void DontCreateViewForTesting() override;
   void SetSize(const gfx::Size& size) override;
   void Focus() override;
@@ skipping 218 matching lines @@
   scoped_refptr<SessionStorageNamespace> session_storage_namespace_;
 
   base::WeakPtrFactory<InterstitialPageImpl> weak_ptr_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(InterstitialPageImpl);
 };
 
 }  // namespace content
 
 #endif  // CONTENT_BROWSER_FRAME_HOST_INTERSTITIAL_PAGE_IMPL_H_