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

chrome/browser/ui/cocoa/clear_browsing_data_controller.mm

 // 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.
 
 #import "chrome/browser/ui/cocoa/clear_browsing_data_controller.h"
 
 #include "base/lazy_instance.h"
 #include "base/mac/mac_util.h"
 #include "base/scoped_nsobject.h"
 #include "chrome/browser/browsing_data_remover.h"
@@ skipping 65 matching lines @@
   // |GetOriginalProfile()| will return the same profile if it is the original
   // profile.
   profile = profile->GetOriginalProfile();
 
   ProfileControllerMap* map = g_profile_controller_map.Pointer();
   DCHECK(map != NULL);
   ProfileControllerMap::iterator it = map->find(profile);
   if (it == map->end()) {
     // Since we don't currently support multiple profiles, this class
     // has not been tested against this case.
-    if (map->size() != 0) {
+    if (!map->empty())
       return nil;
-    }
 
     ClearBrowsingDataController* controller =
         [[self alloc] initWithProfile:profile];
     it = map->insert(std::make_pair(profile, controller)).first;
   }
   return it->second;
 }
 
 - (id)initWithProfile:(Profile*)profile {
   DCHECK(profile);
@@ skipping 159 matching lines @@
                         object:self
                       userInfo:userInfo];
 
   [self closeDialog];
   [[self window] orderOut:self];
   [self setIsClearing:NO];
   remover_ = NULL;
 }
 
 @end