AutoFillProfile: Don't clobber data on self-assignment

chrome/browser/autofill/autofill_profile.cc

 // Copyright (c) 2010 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/autofill/autofill_profile.h"
 
 #include <algorithm>
 #include <list>
 #include <map>
 #include <set>
@@ skipping 361 matching lines @@
   }
 }
 
 bool AutoFillProfile::IsEmpty() const {
   FieldTypeSet types;
   GetAvailableFieldTypes(&types);
   return types.empty();
 }
 
 void AutoFillProfile::operator=(const AutoFillProfile& source) {
+  if (this == &source)
+    return;
+
   label_ = source.label_;
   guid_ = source.guid_;
 
   STLDeleteContainerPairSecondPointers(personal_info_.begin(),
                                        personal_info_.end());
   personal_info_.clear();
 
   FormGroupMap::const_iterator iter;
   for (iter = source.personal_info_.begin();
        iter != source.personal_info_.end();
@@ skipping 103 matching lines @@
       << UTF16ToUTF8(profile.GetFieldText(AutoFillType(ADDRESS_HOME_ZIP)))
       << " "
       << UTF16ToUTF8(profile.GetFieldText(AutoFillType(ADDRESS_HOME_COUNTRY)))
       << " "
       << UTF16ToUTF8(profile.GetFieldText(AutoFillType(
              PHONE_HOME_WHOLE_NUMBER)))
       << " "
       << UTF16ToUTF8(profile.GetFieldText(AutoFillType(
              PHONE_FAX_WHOLE_NUMBER)));
 }