diff --git a/chrome/browser/media/webrtc/native_desktop_media_list.cc b/chrome/browser/media/webrtc/native_desktop_media_list.cc
index 798b4d7b58d92..f5f62407f0d6d 100644
--- a/chrome/browser/media/webrtc/native_desktop_media_list.cc
+++ b/chrome/browser/media/webrtc/native_desktop_media_list.cc
@@ -5,8 +5,11 @@
 #include "chrome/browser/media/webrtc/native_desktop_media_list.h"
 
 #include "base/hash.h"
+#include "base/single_thread_task_runner.h"
 #include "base/strings/utf_string_conversions.h"
 #include "base/task/post_task.h"
+#include "base/threading/thread_restrictions.h"
+#include "build/build_config.h"
 #include "chrome/browser/media/webrtc/desktop_media_list_observer.h"
 #include "chrome/grit/generated_resources.h"
 #include "content/public/browser/browser_thread.h"
@@ -76,11 +79,13 @@ gfx::ImageSkia ScaleDesktopFrame(std::unique_ptr<webrtc::DesktopFrame> frame,
 class NativeDesktopMediaList::Worker
     : public webrtc::DesktopCapturer::Callback {
  public:
-  Worker(base::WeakPtr<NativeDesktopMediaList> media_list,
+  Worker(scoped_refptr<base::SingleThreadTaskRunner> task_runner,
+         base::WeakPtr<NativeDesktopMediaList> media_list,
          DesktopMediaID::Type type,
          std::unique_ptr<webrtc::DesktopCapturer> capturer);
   ~Worker() override;
 
+  void Start();
   void Refresh(const DesktopMediaID::Id& view_dialog_id);
 
   void RefreshThumbnails(const std::vector<DesktopMediaID>& native_ids,
@@ -93,6 +98,9 @@ class NativeDesktopMediaList::Worker
   void OnCaptureResult(webrtc::DesktopCapturer::Result result,
                        std::unique_ptr<webrtc::DesktopFrame> frame) override;
 
+  // Task runner used for capturing operations.
+  scoped_refptr<base::SingleThreadTaskRunner> task_runner_;
+
   base::WeakPtr<NativeDesktopMediaList> media_list_;
 
   DesktopMediaID::Type type_;
@@ -106,17 +114,27 @@ class NativeDesktopMediaList::Worker
 };
 
 NativeDesktopMediaList::Worker::Worker(
+    scoped_refptr<base::SingleThreadTaskRunner> task_runner,
     base::WeakPtr<NativeDesktopMediaList> media_list,
     DesktopMediaID::Type type,
     std::unique_ptr<webrtc::DesktopCapturer> capturer)
-    : media_list_(media_list), type_(type), capturer_(std::move(capturer)) {
-  capturer_->Start(this);
+    : task_runner_(task_runner),
+      media_list_(media_list),
+      type_(type),
+      capturer_(std::move(capturer)) {}
+
+NativeDesktopMediaList::Worker::~Worker() {
+  DCHECK(task_runner_->BelongsToCurrentThread());
 }
 
-NativeDesktopMediaList::Worker::~Worker() {}
+void NativeDesktopMediaList::Worker::Start() {
+  DCHECK(task_runner_->BelongsToCurrentThread());
+  capturer_->Start(this);
+}
 
 void NativeDesktopMediaList::Worker::Refresh(
     const DesktopMediaID::Id& view_dialog_id) {
+  DCHECK(task_runner_->BelongsToCurrentThread());
   std::vector<SourceDescription> result;
 
   webrtc::DesktopCapturer::SourceList sources;
@@ -163,6 +181,7 @@ void NativeDesktopMediaList::Worker::Refresh(
 void NativeDesktopMediaList::Worker::RefreshThumbnails(
     const std::vector<DesktopMediaID>& native_ids,
     const gfx::Size& thumbnail_size) {
+  DCHECK(task_runner_->BelongsToCurrentThread());
   ImageHashesMap new_image_hashes;
 
   // Get a thumbnail for each native source.
@@ -210,17 +229,30 @@ NativeDesktopMediaList::NativeDesktopMediaList(
     std::unique_ptr<webrtc::DesktopCapturer> capturer)
     : DesktopMediaListBase(base::TimeDelta::FromMilliseconds(
           kDefaultNativeDesktopMediaListUpdatePeriod)),
+      thread_("DesktopMediaListCaptureThread"),
       weak_factory_(this) {
   type_ = type;
-  capture_task_runner_ = base::CreateSequencedTaskRunnerWithTraits(
-      {base::MayBlock(), base::TaskPriority::USER_VISIBLE});
 
-  worker_.reset(
-      new Worker(weak_factory_.GetWeakPtr(), type, std::move(capturer)));
+#if defined(OS_WIN) || defined(OS_MACOSX)
+  // On Windows/OSX the thread must be a UI thread.
+  base::MessageLoop::Type thread_type = base::MessageLoop::TYPE_UI;
+#else
+  base::MessageLoop::Type thread_type = base::MessageLoop::TYPE_DEFAULT;
+#endif
+  thread_.StartWithOptions(base::Thread::Options(thread_type, 0));
+
+  worker_.reset(new Worker(thread_.task_runner(), weak_factory_.GetWeakPtr(),
+                           type, std::move(capturer)));
+
+  thread_.task_runner()->PostTask(
+      FROM_HERE,
+      base::BindOnce(&Worker::Start, base::Unretained(worker_.get())));
 }
 
 NativeDesktopMediaList::~NativeDesktopMediaList() {
-  capture_task_runner_->DeleteSoon(FROM_HERE, worker_.release());
+  base::ThreadRestrictions::ScopedAllowIO allow_io;
+  thread_.task_runner()->DeleteSoon(FROM_HERE, worker_.release());
+  thread_.Stop();
 }
 
 void NativeDesktopMediaList::Refresh() {
@@ -230,7 +262,7 @@ void NativeDesktopMediaList::Refresh() {
   new_aura_thumbnail_hashes_.clear();
 #endif
 
-  capture_task_runner_->PostTask(
+  thread_.task_runner()->PostTask(
       FROM_HERE,
       base::BindOnce(&Worker::Refresh, base::Unretained(worker_.get()),
                      view_dialog_id_.id));
@@ -280,7 +312,7 @@ void NativeDesktopMediaList::RefreshForAuraWindows(
 #if defined(USE_AURA)
     pending_native_thumbnail_capture_ = true;
 #endif
-    capture_task_runner_->PostTask(
+    thread_.task_runner()->PostTask(
         FROM_HERE, base::BindOnce(&Worker::RefreshThumbnails,
                                   base::Unretained(worker_.get()), native_ids,
                                   thumbnail_size_));
diff --git a/chrome/browser/media/webrtc/native_desktop_media_list.h b/chrome/browser/media/webrtc/native_desktop_media_list.h
index e6f0e17b05ee4..75c9ca04ce481 100644
--- a/chrome/browser/media/webrtc/native_desktop_media_list.h
+++ b/chrome/browser/media/webrtc/native_desktop_media_list.h
@@ -8,7 +8,7 @@
 #include <memory>
 
 #include "base/memory/weak_ptr.h"
-#include "base/sequenced_task_runner.h"
+#include "base/threading/thread.h"
 #include "chrome/browser/media/webrtc/desktop_media_list_base.h"
 #include "content/public/browser/desktop_media_id.h"
 #include "ui/gfx/image/image.h"
@@ -44,12 +44,7 @@ class NativeDesktopMediaList : public DesktopMediaListBase {
                                gfx::Image image);
 #endif
 
-  // Task runner used for the |worker_|.
-  scoped_refptr<base::SequencedTaskRunner> capture_task_runner_;
-
-  // An object that does all the work of getting list of sources on a background
-  // thread (see |capture_task_runner_|). Destroyed on |capture_task_runner_|
-  // after the model is destroyed.
+  base::Thread thread_;
   std::unique_ptr<Worker> worker_;
 
 #if defined(USE_AURA)