Makes RenderFrameObserver/RenderViewObserver::OnDestruct pure virtual.

components/autofill/content/renderer/page_click_tracker.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 COMPONENTS_AUTOFILL_CONTENT_RENDERER_PAGE_CLICK_TRACKER_H_
 #define COMPONENTS_AUTOFILL_CONTENT_RENDERER_PAGE_CLICK_TRACKER_H_
 
 #include <vector>
 
 #include "base/macros.h"
@@ skipping 34 matching lines @@
     void OnMouseDown(const blink::WebNode& mouse_down_node) override;
     void FocusChangeComplete() override;
 
    private:
     PageClickTracker* tracker_;
   };
   friend class Legacy;
 
   // RenderFrameObserver implementation.
   void FocusedNodeChanged(const blink::WebNode& node) override;
+  void OnDestruct() override;
 
   // RenderViewObserver methods forwarded from Legacy. Should be
   // merged into RenderFrameObserver.
   void OnMouseDown(const blink::WebNode& mouse_down_node);
   void FocusChangeComplete();
   void DoFocusChangeComplete();
 
   // True when the last click was on the focused node.
   bool focused_node_was_last_clicked_;
 
   // This is set to false when the focus changes, then set back to true soon
   // afterwards. This helps track whether an event happened after a node was
   // already focused, or if it caused the focus to change.
   bool was_focused_before_now_;
 
   // The listener getting the actual notifications.
   PageClickListener* listener_;
 
   Legacy legacy_;
 
   DISALLOW_COPY_AND_ASSIGN(PageClickTracker);
 };
 
 }  // namespace autofill
 
 #endif  // COMPONENTS_AUTOFILL_CONTENT_RENDERER_PAGE_CLICK_TRACKER_H_