Makes RenderFrameObserver/RenderViewObserver::OnDestruct pure virtual.

chrome/renderer/content_settings_observer.cc

 // Copyright (c) 2012 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 "chrome/renderer/content_settings_observer.h"
 
 #include "base/command_line.h"
 #include "base/metrics/histogram.h"
 #include "components/content_settings/content/common/content_settings_messages.h"
 #include "content/public/common/url_constants.h"
@@ skipping 230 matching lines @@
     temporarily_allowed_plugins_.clear();
   }
 
   GURL url = frame->document().url();
   // If we start failing this DCHECK, please makes sure we don't regress
   // this bug: http://code.google.com/p/chromium/issues/detail?id=79304
   DCHECK(frame->document().getSecurityOrigin().toString() == "null" ||
          !url.SchemeIs(url::kDataScheme));
 }
 
+void ContentSettingsObserver::OnDestruct() {
+  delete this;
+}
+
 bool ContentSettingsObserver::allowDatabase(const WebString& name,
                                             const WebString& display_name,
                                             unsigned long estimated_size) {
   WebFrame* frame = render_frame()->GetWebFrame();
   if (frame->getSecurityOrigin().isUnique() ||
       frame->top()->getSecurityOrigin().isUnique())
     return false;
 
   bool result = false;
   Send(new ChromeViewHostMsg_AllowDatabase(
@@ skipping 362 matching lines @@
 
   // If the scheme is file:, an empty file name indicates a directory listing,
   // which requires JavaScript to function properly.
   if (base::EqualsASCII(protocol, url::kFileScheme)) {
     return document_url.SchemeIs(url::kFileScheme) &&
            document_url.ExtractFileName().empty();
   }
 
   return false;
 }