network service: pass PlzNavigate resulting data via mojo data pipe

content/child/web_url_loader_impl.h

Index: content/child/web_url_loader_impl.h
diff --git a/content/child/web_url_loader_impl.h b/content/child/web_url_loader_impl.h
index 5f8eef6d8cccbfe39618107120ca16507e6e0e0a..a3825703dcfee6fbdb6f0917de9a4b874adfd6b0 100644
--- a/content/child/web_url_loader_impl.h
+++ b/content/child/web_url_loader_impl.h
@@ -10,6 +10,7 @@
 #include "content/common/content_export.h"
 #include "content/common/url_loader_factory.mojom.h"
 #include "content/public/common/resource_response.h"
+#include "mojo/public/cpp/system/data_pipe.h"
 #include "net/url_request/redirect_info.h"
 #include "third_party/WebKit/public/platform/WebURLLoader.h"
 #include "url/gurl.h"
@@ -27,6 +28,7 @@ struct CONTENT_EXPORT StreamOverrideParameters {
   // TODO(clamy): The browser should be made aware on destruction of this struct
   // that it can release its associated stream handle.
   GURL stream_url;
+  mojo::ScopedDataPipeConsumerHandle consumer_handle;
   ResourceResponseHead response;
   std::vector<GURL> redirects;
   std::vector<ResourceResponseInfo> redirect_responses;
@@ -35,6 +37,8 @@ struct CONTENT_EXPORT StreamOverrideParameters {
   // The delta between the actual transfer size and the one reported by the
   // AsyncResourceLoader due to not having the ResourceResponse.
   int total_transfer_size_delta;
+
+  int total_transferred = 0;
 };
 
 class CONTENT_EXPORT WebURLLoaderImpl