Add HttpProtocolHandler and convert everything to use it

net/url_request/url_request_test_util.h

Index: net/url_request/url_request_test_util.h
diff --git a/net/url_request/url_request_test_util.h b/net/url_request/url_request_test_util.h
index 0de30427b305b842f2e0e1acc6792eaa99630018..64a7052f2459117d18f958440ada034f69ca3778 100644
--- a/net/url_request/url_request_test_util.h
+++ b/net/url_request/url_request_test_util.h
@@ -38,10 +38,12 @@
 #include "net/http/http_request_headers.h"
 #include "net/proxy/proxy_service.h"
 #include "net/ssl/ssl_config_service_defaults.h"
+#include "net/url_request/http_protocol_handler.h"
 #include "net/url_request/url_request.h"
 #include "net/url_request/url_request_context.h"
 #include "net/url_request/url_request_context_getter.h"
 #include "net/url_request/url_request_context_storage.h"
+#include "net/url_request/url_request_interceptor.h"
 #include "net/url_request/url_request_job_factory.h"
 #include "url/url_util.h"
 
@@ -405,13 +407,21 @@ class TestNetworkDelegate : public NetworkDelegateImpl {
 
 //-----------------------------------------------------------------------------
 
-// A simple ProtocolHandler that returns a pre-built URLRequestJob only once.
-class TestJobInterceptor : public URLRequestJobFactory::ProtocolHandler {
+// A simple ProtocolHandler that returns a pre-built URLRequestJob only once,
+// and falls back to a normal HttpProtocolHandler implementation if no pre-built
+// URLRequestJob is present.
+class TestJobInterceptor : public URLRequestInterceptor {
  public:
   TestJobInterceptor();
   ~TestJobInterceptor() override;
 
-  URLRequestJob* MaybeCreateJob(
+  URLRequestJob* MaybeInterceptRequest(
+      URLRequest* request,
+      NetworkDelegate* network_delegate) const override;
+  URLRequestJob* MaybeInterceptRedirect(URLRequest* request,
+                                        NetworkDelegate* network_delegate,
+                                        const GURL& location) const override;
+  URLRequestJob* MaybeInterceptResponse(
       URLRequest* request,
       NetworkDelegate* network_delegate) const override;
   void set_main_intercept_job(std::unique_ptr<URLRequestJob> job);