Don't re-save autofill profiles to the web database if they haven't changed.

chrome/browser/webdata/web_database.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/webdata/web_database.h"
 
 #include <algorithm>
 #include <limits>
 #include <set>
 #include <string>
@@ skipping 1675 matching lines @@
   }
 
   while (s.Step())
     profiles->push_back(AutoFillProfileFromStatement(s));
 
   return s.Succeeded();
 }
 
 bool WebDatabase::UpdateAutoFillProfile(const AutoFillProfile& profile) {
   DCHECK(guid::IsValidGUID(profile.guid()));
+
+  // Preserve appropriate modification dates by not updating unchanged profiles.
+  AutoFillProfile* tmp_profile = NULL;
+  DCHECK(GetAutoFillProfileForGUID(profile.guid(), &tmp_profile));
+  scoped_ptr<AutoFillProfile> old_profile(tmp_profile);
+  if (*old_profile == profile)
+    return true;
+
   sql::Statement s(db_.GetUniqueStatement(
       "UPDATE autofill_profiles "
       "SET guid=?, label=?, first_name=?, middle_name=?, last_name=?, "
       "    email=?, company_name=?, address_line_1=?, address_line_2=?, "
       "    city=?, state=?, zipcode=?, country=?, phone=?, fax=?, "
       "    date_modified=? "
       "WHERE guid=?"));
   if (!s) {
     NOTREACHED() << "Statement prepare failed";
     return false;
@@ skipping 100 matching lines @@
   }
 
   while (s.Step())
     credit_cards->push_back(CreditCardFromStatement(s));
 
   return s.Succeeded();
 }
 
 bool WebDatabase::UpdateCreditCard(const CreditCard& credit_card) {
   DCHECK(guid::IsValidGUID(credit_card.guid()));
+
+  // Preserve appropriate modification dates by not updating unchanged cards.
+  CreditCard* tmp_credit_card = NULL;
+  DCHECK(GetCreditCardForGUID(credit_card.guid(), &tmp_credit_card));
+  scoped_ptr<CreditCard> old_credit_card(tmp_credit_card);
+  if (*old_credit_card == credit_card)
+    return true;
+
   sql::Statement s(db_.GetUniqueStatement(
       "UPDATE credit_cards "
       "SET guid=?, label=?, name_on_card=?, expiration_month=?, "
       "    expiration_year=?, card_number_encrypted=?, date_modified=? "
       "WHERE guid=?"));
   if (!s) {
     NOTREACHED() << "Statement prepare failed";
     return false;
   }
 
@@ skipping 731 matching lines @@
 
     // Add successive versions here.  Each should set the version number and
     // compatible version number as appropriate, then fall through to the next
     // case.
 
     case kCurrentVersionNumber:
       // No migration needed.
       return sql::INIT_OK;
   }
 }