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

chrome/browser/sync/glue/foreign_session_tracker.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/sync/glue/foreign_session_tracker.h"
 #include "chrome/browser/sync/glue/session_model_associator.h"
 
 namespace browser_sync {
 
 
 ForeignSessionTracker::ForeignSessionTracker() {
 }
 
 ForeignSessionTracker::~ForeignSessionTracker() {
   clear();
 }
 
 bool ForeignSessionTracker::LookupAllForeignSessions(
     std::vector<const ForeignSession*>* sessions) {
   DCHECK(sessions);
   // Fill vector of sessions from our foreign session map.
   for (ForeignSessionMap::const_iterator i =
     foreign_session_map_.begin(); i != foreign_session_map_.end(); ++i) {
     // Only include sessions with open tabs.
     ForeignSession* foreign_session = i->second;
-    if (foreign_session->windows.size() > 0 &&
+    if (!foreign_session->windows.empty() &&
         !SessionModelAssociator::SessionWindowHasNoTabsToSync(
             *foreign_session->windows[0])) {
       sessions->push_back(foreign_session);
     }
   }
 
-  if (sessions->size() > 0)
-    return true;
-  else
-    return false;
+  return !sessions->empty();
 }
 
 bool ForeignSessionTracker::LookupSessionWindows(
     const std::string& foreign_session_tag,
     std::vector<SessionWindow*>* windows) {
   DCHECK(windows);
   ForeignSessionMap::iterator iter = foreign_session_map_.find(
       foreign_session_tag);
   if (iter == foreign_session_map_.end())
     return false;
@@ skipping 87 matching lines @@
       foreign_tab_map_.end());
   foreign_tab_map_.clear();
 
   // Go through and delete any tabs we had allocated but had not yet placed into
   // a ForeignSessionobject.
   STLDeleteContainerPointers(unmapped_tabs_.begin(), unmapped_tabs_.end());
   unmapped_tabs_.clear();
 }
 
 }  // namespace browser_sync