Makes RenderFrameObserver/RenderViewObserver::OnDestruct pure virtual.

components/autofill/content/renderer/page_click_tracker.cc

 // 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.
 
 #include "components/autofill/content/renderer/page_click_tracker.h"
 
 #include "base/command_line.h"
 #include "components/autofill/content/renderer/form_autofill_util.h"
 #include "components/autofill/content/renderer/page_click_listener.h"
 #include "components/autofill/core/common/autofill_util.h"
@@ skipping 85 matching lines @@
     if (!control.isNull()) {
       listener_->FormControlElementClicked(control,
                                            was_focused_before_now_);
     }
   }
 
   was_focused_before_now_ = true;
   focused_node_was_last_clicked_ = false;
 }
 
+void PageClickTracker::OnDestruct() {
+  delete this;
+}
+
 // PageClickTracker::Legacy ----------------------------------------------------
 
 PageClickTracker::Legacy::Legacy(PageClickTracker* tracker)
     : content::RenderViewObserver(tracker->render_frame()->GetRenderView()),
       tracker_(tracker) {
 }
 
 void PageClickTracker::Legacy::OnDestruct() {
   // No-op. Don't delete |this|.
 }
 
 void PageClickTracker::Legacy::OnMouseDown(const WebNode& mouse_down_node) {
   tracker_->OnMouseDown(mouse_down_node);
 }
 
 void PageClickTracker::Legacy::FocusChangeComplete() {
   tracker_->FocusChangeComplete();
 }
 
 }  // namespace autofill