Add comments for struct members that were changed from size_t to uin32_t or uint64_t for IPC safety.

chrome/browser/task_manager/task_manager.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/browser/task_manager/task_manager.h"
 
 #include "base/bind.h"
 #include "base/i18n/number_formatting.h"
 #include "base/i18n/rtl.h"
 #include "base/location.h"
+#include "base/numerics/safe_conversions.h"
 #include "base/process/process_metrics.h"
 #include "base/single_thread_task_runner.h"
 #include "base/stl_util.h"
 #include "base/strings/string16.h"
 #include "base/strings/string_number_conversions.h"
 #include "base/strings/stringprintf.h"
 #include "base/strings/utf_string_conversions.h"
 #include "base/thread_task_runner_handle.h"
 #include "build/build_config.h"
 #include "chrome/browser/browser_process.h"
@@ skipping 638 matching lines @@
 
   base::ProcessId pid = GetProcessId(index);
   PerProcessValues& values(
       per_process_cache_[GetResource(index)->GetProcess()]);
   if (!values.is_video_memory_valid) {
     content::GPUVideoMemoryUsageStats::ProcessMap::const_iterator i =
         video_memory_usage_stats_.process_map.find(pid);
     if (i == video_memory_usage_stats_.process_map.end())
       return false;
     values.is_video_memory_valid = true;
-    values.video_memory = i->second.video_memory;
+    // If this checked_cast asserts, then need to change this code to use
+    // uint64_t instead of size_t.
+    values.video_memory = base::checked_cast<size_t>(i->second.video_memory);
     values.video_memory_has_duplicates = i->second.has_duplicates;
   }
   *video_memory = values.video_memory;
   *has_duplicates = values.video_memory_has_duplicates;
   return true;
 }
 
 bool TaskManagerModel::GetSqliteMemoryUsedBytes(
     int index,
     size_t* result) const {
@@ skipping 890 matching lines @@
   params.host_desktop_type = desktop_type;
   chrome::Navigate(&params);
 }
 
 TaskManager::TaskManager()
     : model_(new TaskManagerModel(this)) {
 }
 
 TaskManager::~TaskManager() {
 }