Refactor Pickle Read methods to use higher performance PickleIterator.

chrome/renderer/extensions/user_script_slave.cc

 // Copyright (c) 2012 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/renderer/extensions/user_script_slave.h"
 
 #include <map>
 
 #include "base/command_line.h"
 #include "base/logging.h"
@@ skipping 137 matching lines @@
   Pickle::Header* pickle_header =
       reinterpret_cast<Pickle::Header*>(shared_memory_->memory());
 
   // Now map in the rest of the block.
   int pickle_size = sizeof(Pickle::Header) + pickle_header->payload_size;
   shared_memory_->Unmap();
   if (!shared_memory_->Map(pickle_size))
     return false;
 
   // Unpickle scripts.
-  void* iter = NULL;
   size_t num_scripts = 0;
   Pickle pickle(reinterpret_cast<char*>(shared_memory_->memory()),
                 pickle_size);
+  PickleIterator iter(pickle);
   pickle.ReadSize(&iter, &num_scripts);
 
   scripts_.reserve(num_scripts);
   for (size_t i = 0; i < num_scripts; ++i) {
     scripts_.push_back(new UserScript());
     UserScript* script = scripts_.back();
     script->Unpickle(pickle, &iter);
 
     // Note that this is a pointer into shared memory. We don't own it. It gets
     // cleared up when the last renderer or browser process drops their
@@ skipping 161 matching lines @@
     if (num_scripts)
       UMA_HISTOGRAM_TIMES("Extensions.InjectEnd_Time", timer.Elapsed());
   } else if (location == UserScript::DOCUMENT_IDLE) {
     UMA_HISTOGRAM_COUNTS_100("Extensions.InjectIdle_ScriptCount", num_scripts);
     if (num_scripts)
       UMA_HISTOGRAM_TIMES("Extensions.InjectIdle_Time", timer.Elapsed());
   } else {
     NOTREACHED();
   }
 }