Change other usages of .size() to .empty() when applicable.

chrome/browser/webdata/web_data_service.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/webdata/web_data_service.h"
 
 #include "base/message_loop.h"
 #include "base/stl_util-inl.h"
 #include "base/task.h"
 #include "base/threading/thread.h"
@@ skipping 930 matching lines @@
 }
 
 void WebDataService::RemoveFormElementsAddedBetweenImpl(
     GenericRequest2<Time, Time>* request) {
   InitializeDatabaseIfNecessary();
   if (db_ && !request->IsCancelled()) {
     AutofillChangeList changes;
     if (db_->RemoveFormElementsAddedBetween(request->GetArgument1(),
                                             request->GetArgument2(),
                                             &changes)) {
-      if (changes.size() > 0) {
+      if (!changes.empty()) {
         request->SetResult(
             new WDResult<AutofillChangeList>(AUTOFILL_CHANGES, changes));
 
         // Post the notifications including the list of affected keys.
         // This is sent here so that work resulting from this notification
         // will be done on the DB thread, and not the UI thread.
         NotificationService::current()->Notify(
             NotificationType::AUTOFILL_ENTRIES_CHANGED,
             Source<WebDataService>(this),
             Details<AutofillChangeList>(&changes));
@@ skipping 274 matching lines @@
   return result_;
 }
 
 void WebDataService::WebDataRequest::RequestComplete() {
   WebDataService* s = service_;
   Task* t = NewRunnableMethod(s,
                               &WebDataService::RequestCompleted,
                               handle_);
   message_loop_->PostTask(FROM_HERE, t);
 }