Add support in the network service for different contexts.

content/browser/loader/navigation_url_loader_network_service.h

Index: content/browser/loader/navigation_url_loader_network_service.h
diff --git a/content/browser/loader/navigation_url_loader_network_service.h b/content/browser/loader/navigation_url_loader_network_service.h
index 50ff253a9a2b0af666b92b0e8decea2630776eca..9e7af001a1c78cc84855ff8a7745d47a1f0c8bfd 100644
--- a/content/browser/loader/navigation_url_loader_network_service.h
+++ b/content/browser/loader/navigation_url_loader_network_service.h
@@ -7,7 +7,6 @@
 
 #include "base/macros.h"
 #include "content/browser/loader/navigation_url_loader.h"
-#include "content/common/content_export.h"
 #include "content/common/url_loader.mojom.h"
 #include "content/common/url_loader_factory.mojom.h"
 #include "content/public/browser/ssl_status.h"
@@ -39,11 +38,6 @@ class NavigationURLLoaderNetworkService : public NavigationURLLoader,
       NavigationURLLoaderDelegate* delegate);
   ~NavigationURLLoaderNetworkService() override;
 
-  // Overrides the URLLoaderFactory for subsequent requests. Passing a null
-  // pointer will restore the default behavior.
-  static CONTENT_EXPORT void OverrideURLLoaderFactoryForTesting(
-      mojom::URLLoaderFactoryPtr url_loader_factory);
-
   // NavigationURLLoader implementation:
   void FollowRedirect() override;
   void ProceedWithResponse() override;