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

ppapi/proxy/serialized_var.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 "ppapi/proxy/serialized_var.h"
 
 #include "base/logging.h"
 #include "ipc/ipc_message_utils.h"
 #include "ppapi/proxy/dispatcher.h"
 #include "ppapi/proxy/interface_proxy.h"
@@ skipping 385 matching lines @@
 
     serialized_[i].inner_->SetVar(
         serialized_[i].inner_->serialization_rules()->BeginReceiveCallerOwned(
             serialized_[i].inner_->GetIncompleteVar(),
             serialized_[i].inner_->GetStringPtr(),
             dispatcher));
     deserialized_[i] = serialized_[i].inner_->GetVar();
   }
 
   *array_size = static_cast<uint32_t>(serialized_.size());
-  return deserialized_.size() > 0 ? &deserialized_[0] : NULL;
+  return deserialized_.empty() ? NULL : &deserialized_[0];
 }
 
 // SerializedVarReturnValue ----------------------------------------------------
 
 SerializedVarReturnValue::SerializedVarReturnValue(SerializedVar* serialized)
     : serialized_(serialized) {
 }
 
 void SerializedVarReturnValue::Return(Dispatcher* dispatcher,
                                       const PP_Var& var) {
@@ skipping 100 matching lines @@
   *inner_->GetStringPtr() = str;
 }
 
 SerializedVarTestReader::SerializedVarTestReader(const SerializedVar& var)
     : SerializedVar(var) {
 }
 
 }  // namespace proxy
 }  // namespace pp