dom-ui settings: Stop observing an existing BrowserDataRemover before creating a new one.

chrome/browser/ui/webui/options/clear_browser_data_handler.cc

 // Copyright (c) 2011 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/browser/ui/webui/options/clear_browser_data_handler.h"
 
 #include "base/basictypes.h"
 #include "base/string16.h"
 #include "base/values.h"
 #include "chrome/browser/browser_process.h"
@@ skipping 107 matching lines @@
     remove_mask |= BrowsingDataRemover::REMOVE_PASSWORDS;
   if (prefs->GetBoolean(prefs::kDeleteFormData))
     remove_mask |= BrowsingDataRemover::REMOVE_FORM_DATA;
 
   int period_selected = prefs->GetInteger(prefs::kDeleteTimePeriod);
 
   FundamentalValue state(true);
   web_ui_->CallJavascriptFunction("ClearBrowserDataOverlay.setClearingState",
                                   state);
 
+  // If we are still observing a previous data remover, we need to stop
+  // observing.
+  if (remover_) {
+    remover_->RemoveObserver(this);
+  }

[James Hawkins, 2011/05/20 21:09:37]

nit: No need for braces.

[csilv, 2011/05/20 21:11:54]

Done.

+
   // BrowsingDataRemover deletes itself when done.
   remover_ = new BrowsingDataRemover(profile,
       static_cast<BrowsingDataRemover::TimePeriod>(period_selected),
       base::Time());
   remover_->AddObserver(this);
   remover_->Remove(remove_mask);
 }
 
 void ClearBrowserDataHandler::OnBrowsingDataRemoverDone() {
   // No need to remove ourselves as an observer as BrowsingDataRemover deletes
   // itself after we return.
   remover_ = NULL;
   DCHECK(web_ui_);
   web_ui_->CallJavascriptFunction("ClearBrowserDataOverlay.doneClearing");
 }