Request_sender must not use the worker pool to construct an URLFetcher,

as this causes a crash. Instead, the class will post to the same thread
that is already running on.

A thread checker has been added to check thread affinity.

BUG=432307

Review URL: https://codereview.chromium.org/729013002

Cr-Commit-Position: refs/heads/master@{#304308}

2 files changed, 10 insertions, 2 deletions

diff --git a/components/component_updater/request_sender.cc b/components/component_updater/request_sender.cc
index 8c80622..da6f794 100644
--- a/components/component_updater/request_sender.cc
+++ b/components/component_updater/request_sender.cc
@@ -8,7 +8,8 @@
 #include "base/bind_helpers.h"
 #include "base/location.h"
 #include "base/logging.h"
-#include "base/sequenced_task_runner.h"
+#include "base/single_thread_task_runner.h"
+#include "base/thread_task_runner_handle.h"
 #include "components/component_updater/component_updater_configurator.h"
 #include "components/component_updater/component_updater_utils.h"
 #include "net/url_request/url_fetcher.h"
@@ -19,11 +20,13 @@ RequestSender::RequestSender(const Configurator& config) : config_(config) {
 }
 
 RequestSender::~RequestSender() {
+  DCHECK(thread_checker_.CalledOnValidThread());
 }
 
 void RequestSender::Send(const std::string& request_string,
                          const std::vector<GURL>& urls,
                          const RequestSenderCallback& request_sender_callback) {
+  DCHECK(thread_checker_.CalledOnValidThread());
   if (urls.empty()) {
     request_sender_callback.Run(NULL);
     return;
@@ -41,19 +44,21 @@ void RequestSender::Send(const std::string& request_string,
 void RequestSender::SendInternal() {
   DCHECK(cur_url_ != urls_.end());
   DCHECK(cur_url_->is_valid());
+  DCHECK(thread_checker_.CalledOnValidThread());
 
   url_fetcher_.reset(SendProtocolRequest(
       *cur_url_, request_string_, this, config_.RequestContext()));
 }
 
 void RequestSender::OnURLFetchComplete(const net::URLFetcher* source) {
+  DCHECK(thread_checker_.CalledOnValidThread());
   if (GetFetchError(*source) == 0) {
     request_sender_callback_.Run(source);
     return;
   }
 
   if (++cur_url_ != urls_.end() &&
-      config_.GetSequencedTaskRunner()->PostTask(
+      base::ThreadTaskRunnerHandle::Get()->PostTask(
           FROM_HERE,
           base::Bind(&RequestSender::SendInternal, base::Unretained(this)))) {
     return;
diff --git a/components/component_updater/request_sender.h b/components/component_updater/request_sender.h
index 10a26f8..5d137e2 100644
--- a/components/component_updater/request_sender.h
+++ b/components/component_updater/request_sender.h
@@ -12,6 +12,7 @@
 #include "base/compiler_specific.h"
 #include "base/macros.h"
 #include "base/memory/scoped_ptr.h"
+#include "base/threading/thread_checker.h"
 #include "net/url_request/url_fetcher_delegate.h"
 #include "url/gurl.h"
 
@@ -53,6 +54,8 @@ class RequestSender : public net::URLFetcherDelegate {
   std::string request_string_;
   RequestSenderCallback request_sender_callback_;
 
+  base::ThreadChecker thread_checker_;
+
   DISALLOW_COPY_AND_ASSIGN(RequestSender);
 };