Use ExternalFileSystemBackend in the DriveURLRequestJob.

chrome/browser/chromeos/drive/drive_protocol_handler.cc

Index: chrome/browser/chromeos/drive/drive_protocol_handler.cc
diff --git a/chrome/browser/chromeos/drive/drive_protocol_handler.cc b/chrome/browser/chromeos/drive/drive_protocol_handler.cc
index 227fc7ac110c206af04f4075522e18db94ae5548..78db9d3e874eaf800ac81d931883cde52c6973c0 100644
--- a/chrome/browser/chromeos/drive/drive_protocol_handler.cc
+++ b/chrome/browser/chromeos/drive/drive_protocol_handler.cc
@@ -5,23 +5,14 @@
 #include "chrome/browser/chromeos/drive/drive_protocol_handler.h"
 
 #include "base/logging.h"
-#include "base/threading/sequenced_worker_pool.h"
 #include "chrome/browser/chromeos/drive/drive_url_request_job.h"
-#include "chrome/browser/chromeos/drive/file_system_util.h"
-#include "content/public/browser/browser_thread.h"
 #include "net/url_request/url_request.h"
 #include "url/gurl.h"
 
-using content::BrowserThread;
-
 namespace drive {
 
 DriveProtocolHandler::DriveProtocolHandler(void* profile_id)
     : profile_id_(profile_id) {
-  scoped_refptr<base::SequencedWorkerPool> blocking_pool =
-      BrowserThread::GetBlockingPool();
-  blocking_task_runner_ =
-      blocking_pool->GetSequencedTaskRunner(blocking_pool->GetSequenceToken());
 }
 
 DriveProtocolHandler::~DriveProtocolHandler() {
@@ -31,8 +22,7 @@ net::URLRequestJob* DriveProtocolHandler::MaybeCreateJob(
     net::URLRequest* request, net::NetworkDelegate* network_delegate) const {
   DVLOG(1) << "Handling url: " << request->url().spec();
   return new DriveURLRequestJob(
-      base::Bind(&util::GetFileSystemByProfileId, profile_id_),
-      blocking_task_runner_.get(),
+      profile_id_,
       request,
       network_delegate);
 }