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

chrome/browser/sync/glue/data_type_manager_impl2.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/sync/glue/data_type_manager_impl2.h"
 
 #include "base/compiler_specific.h"
 #include "base/logging.h"
 #include "chrome/browser/sync/glue/data_type_controller.h"
 #include "chrome/browser/sync/glue/sync_backend_host.h"
@@ skipping 168 matching lines @@
     return;
   }
 
   state_ = CONFIGURING;
   StartNextType();
 }
 
 void DataTypeManagerImpl2::StartNextType() {
   // If there are any data types left to start, start the one at the
   // front of the list.
-  if (needs_start_.size() > 0) {
+  if (!needs_start_.empty()) {
     current_dtc_ = needs_start_[0];
     VLOG(1) << "Starting " << current_dtc_->name();
     current_dtc_->Start(
         NewCallback(this, &DataTypeManagerImpl2::TypeStartCallback));
     return;
   }
 
   // If no more data types need starting, we're done.
   DCHECK_EQ(state_, CONFIGURING);
   state_ = CONFIGURED;
@@ skipping 128 matching lines @@
 
 const DataTypeController::TypeMap& DataTypeManagerImpl2::controllers() {
   return controllers_;
 }
 
 DataTypeManager::State DataTypeManagerImpl2::state() {
   return state_;
 }
 
 }  // namespace browser_sync