Implement NavigationThrottle::BLOCK_REQUEST_AND_COLLAPSE.

third_party/WebKit/Source/core/frame/FrameOwner.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 FrameOwner_h
 #define FrameOwner_h
 
 #include "core/CoreExport.h"
 #include "core/dom/SandboxFlags.h"
 #include "platform/heap/Handle.h"
@@ skipping 20 matching lines @@
   virtual void clearContentFrame() = 0;
 
   virtual SandboxFlags getSandboxFlags() const = 0;
   virtual void dispatchLoad() = 0;
 
   // On load failure, a frame can ask its owner to render fallback content
   // which replaces the frame contents.
   virtual bool canRenderFallbackContent() const = 0;
   virtual void renderFallbackContent() = 0;
 
+  // Collapses the frame owner, i.e. removes it from the layout of the parent
+  // frame if the owner is an <iframe> element.
+  virtual void setShouldCollapse(bool) {}
+
   virtual ScrollbarMode scrollingMode() const = 0;
   virtual int marginWidth() const = 0;
   virtual int marginHeight() const = 0;
   virtual bool allowFullscreen() const = 0;
   virtual bool allowPaymentRequest() const = 0;
   virtual AtomicString csp() const = 0;
   virtual const WebVector<WebPermissionType>& delegatedPermissions() const = 0;
 };
 
 class CORE_EXPORT DummyFrameOwner
@@ skipping 27 matching lines @@
  private:
   // Intentionally private to prevent redundant checks when the type is
   // already DummyFrameOwner.
   bool isLocal() const override { return false; }
   bool isRemote() const override { return false; }
 };
 
 }  // namespace blink
 
 #endif  // FrameOwner_h