Use URLRequestJobManager to retry data reduction proxy bypasses

The data reduction proxy retries a bypassed request by creating
a new URLRequestHttpJob for the request and starting it. This
change uses URLRequestJobManager::CreateJob() to create that job.
Previously, the URLRequestJobFactory chain was called to create
the job, an it only would for main frame requests.

BUG=434830

Review URL: https://codereview.chromium.org/740643003

Cr-Commit-Position: refs/heads/master@{#305054}

components/data_reduction_proxy/core/browser/data_reduction_proxy_interceptor.cc

@@ -12,7 +12,7 @@
 #include "net/url_request/url_request.h"
 #include "net/url_request/url_request_context.h"
 #include "net/url_request/url_request_http_job.h"
-#include "net/url_request/url_request_job_factory.h"
+#include "net/url_request/url_request_job_manager.h"
 #include "url/url_constants.h"
 
 namespace data_reduction_proxy {
@@ -48,8 +48,8 @@ net::URLRequestJob* DataReductionProxyInterceptor::MaybeInterceptResponse(
   // Returning non-NULL has the effect of restarting the request with the
   // supplied job.
   DCHECK(request->url().SchemeIs(url::kHttpScheme));
-  return request->context()->job_factory()->MaybeCreateJobWithProtocolHandler(
-      url::kHttpScheme, request, network_delegate);
+  return net::URLRequestJobManager::GetInstance()->CreateJob(
+      request, network_delegate);
 }
 
 }  // namespace data_reduction_proxy

net/url_request/url_request_job_manager.h

@@ -10,6 +10,7 @@
 
 #include "base/synchronization/lock.h"
 #include "base/threading/platform_thread.h"
+#include "net/base/net_export.h"
 #include "net/url_request/url_request.h"
 
 template <typename T> struct DefaultSingletonTraits;
@@ -24,7 +25,7 @@ namespace net {
 //   URLRequest is designed to have all consumers on a single thread, and
 //   so no attempt is made to support Interceptor instances being
 //   registered/unregistered or in any way poked on multiple threads.
-class URLRequestJobManager {
+class NET_EXPORT URLRequestJobManager {
  public:
   // Returns the singleton instance.
   static URLRequestJobManager* GetInstance();