Fix TaskmanagerIoThreadHelper bug.

chrome/browser/task_management/sampling/task_manager_io_thread_helper.cc

 // Copyright 2015 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_management/sampling/task_manager_io_thread_helper.h"
 
 #include "chrome/browser/task_management/sampling/task_manager_impl.h"
 #include "content/public/browser/browser_thread.h"
 #include "content/public/browser/resource_request_info.h"
 
@@ skipping 41 matching lines @@
 
 // static
 void TaskManagerIoThreadHelper::OnRawBytesRead(const net::URLRequest& request,
                                                int64_t bytes_read) {
   DCHECK_CURRENTLY_ON(content::BrowserThread::IO);
 
   if (g_io_thread_helper)
     g_io_thread_helper->OnNetworkBytesRead(request, bytes_read);
 }
 
-TaskManagerIoThreadHelper::TaskManagerIoThreadHelper() {
+TaskManagerIoThreadHelper::TaskManagerIoThreadHelper() : weak_factory_(this) {
   DCHECK_CURRENTLY_ON(content::BrowserThread::IO);
 }
 
 TaskManagerIoThreadHelper::~TaskManagerIoThreadHelper() {
   DCHECK_CURRENTLY_ON(content::BrowserThread::IO);
 }
 
-// static
 void TaskManagerIoThreadHelper::OnMultipleBytesReadIO() {
   DCHECK_CURRENTLY_ON(content::BrowserThread::IO);
 
-  if (!g_io_thread_helper)
-    return;
-
-  DCHECK(!g_io_thread_helper->bytes_read_buffer_.empty());
+  DCHECK(!bytes_read_buffer_.empty());
 
   std::vector<BytesReadParam>* bytes_read_buffer =
       new std::vector<BytesReadParam>();
-  g_io_thread_helper->bytes_read_buffer_.swap(*bytes_read_buffer);
+  bytes_read_buffer_.swap(*bytes_read_buffer);
 
   content::BrowserThread::PostTask(
       content::BrowserThread::UI,
       FROM_HERE,
       base::Bind(&TaskManagerImpl::OnMultipleBytesReadUI,
                  base::Owned(bytes_read_buffer)));
 }
 
 void TaskManagerIoThreadHelper::OnNetworkBytesRead(
     const net::URLRequest& request, int64_t bytes_read) {
@@ skipping 15 matching lines @@
   // plugins - for renderer or browser initiated requests it will be zero.
   int origin_pid = info ? info->GetOriginPID() : 0;
 
   if (bytes_read_buffer_.empty()) {
     // Schedule a task to process the received bytes requests a second from now.
     // We're trying to calculate the tasks' network usage speed as bytes per
     // second so we collect as many requests during one seconds before the below
     // delayed TaskManagerIoThreadHelper::OnMultipleBytesReadIO() process them
     // after one second from now.
     content::BrowserThread::PostDelayedTask(
-        content::BrowserThread::IO,
-        FROM_HERE,
-        base::Bind(TaskManagerIoThreadHelper::OnMultipleBytesReadIO),
+        content::BrowserThread::IO, FROM_HERE,
+        base::Bind(&TaskManagerIoThreadHelper::OnMultipleBytesReadIO,
+                   weak_factory_.GetWeakPtr()),
         base::TimeDelta::FromSeconds(1));
   }
 
   bytes_read_buffer_.push_back(
       BytesReadParam(origin_pid, child_id, route_id, bytes_read));
 }
 
 }  // namespace task_management