Pure pedantry: Replace all ".size() == 0" with ".empty()".

ipc/ipc_message_utils.h

 // 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.
 
 #ifndef IPC_IPC_MESSAGE_UTILS_H_
 #define IPC_IPC_MESSAGE_UTILS_H_
 #pragma once
 
 #include <algorithm>
 #include <string>
@@ skipping 395 matching lines @@
         StringPrintf(" and %u more bytes",
                      static_cast<unsigned>(data.size() - kMaxBytesToLog)));
   }
 #endif
 }
 
 template <>
 struct ParamTraits<std::vector<unsigned char> > {
   typedef std::vector<unsigned char> param_type;
   static void Write(Message* m, const param_type& p) {
-    if (p.size() == 0) {
+    if (p.empty()) {
       m->WriteData(NULL, 0);
     } else {
       m->WriteData(reinterpret_cast<const char*>(&p.front()),
                    static_cast<int>(p.size()));
     }
   }
   static bool Read(const Message* m, void** iter, param_type* r) {
     const char *data;
     int data_size = 0;
     if (!m->ReadData(iter, &data, &data_size) || data_size < 0)
       return false;
     r->resize(data_size);
     if (data_size)
       memcpy(&r->front(), data, data_size);
     return true;
   }
   static void Log(const param_type& p, std::string* l) {
     LogBytes(p, l);
   }
 };
 
 template <>
 struct ParamTraits<std::vector<char> > {
   typedef std::vector<char> param_type;
   static void Write(Message* m, const param_type& p) {
-    if (p.size() == 0) {
+    if (p.empty()) {
       m->WriteData(NULL, 0);
     } else {
       m->WriteData(&p.front(), static_cast<int>(p.size()));
     }
   }
   static bool Read(const Message* m, void** iter, param_type* r) {
     const char *data;
     int data_size = 0;
     if (!m->ReadData(iter, &data, &data_size) || data_size < 0)
       return false;
@@ skipping 742 matching lines @@
     ReplyParam p(a, b, c, d, e);
     WriteParam(reply, p);
   }
 };
 
 //-----------------------------------------------------------------------------
 
 }  // namespace IPC
 
 #endif  // IPC_IPC_MESSAGE_UTILS_H_