net/http: sniffWrite test also in http2 mode
net/http: sniffWrite test also in http2 mode

Change-Id: Ifa9f1ed6a3b8d3f7536f2d315259940335b0ee49
Reviewed-on: https://go-review.googlesource.com/17438
Reviewed-by: Brad Fitzpatrick <ae9783c0b0efc69cd85ab025ddd17aa44cdc4aa5@golang.org>
Run-TryBot: Brad Fitzpatrick <ae9783c0b0efc69cd85ab025ddd17aa44cdc4aa5@golang.org>
TryBot-Result: Gobot Gobot <66cb808b70d30c07676d5e946fee83fd561249e5@golang.org>

theif519/go,mwhudson/go,theif519/go,kim-racktop/go,CAFxX/go,deft-code/go,suncycheng/go,sndnvaps/go,suncycheng/go,sndnvaps/go,Samurais/go,ganboing/go-esx,kim-racktop/go,momchil-velikov/go,momchil-velikov/go,derekmarcotte/go,akutz/go,kim-racktop/go,nawawi/go,goodlang/good,theif519/go,derekmarcotte/go,cloudflare/go,deft-code/go,cloudflare/go,derekmarcotte/go,Cofyc/go,momchil-velikov/go,codestation/go,fjballest/golang,cloudflare/go,cyberroadie/go,josharian/go,roth1002/go,akutz/go,binarycrusader/go,goodlang/good,golang/go,deft-code/go,theif519/go,codestation/go,polyverse-security/go,theif519/go,miolini/go,ImJasonH/go,akutz/go,ganboing/go-esx,ImJasonH/go,binarycrusader/go,suncycheng/go,ImJasonH/go,vsekhar/elastic-go,cloudflare/go,vsekhar/elastic-go,Cofyc/go,ImJasonH/go,odeke-em/go,suncycheng/go,vanloswang/go,nawawi/go,deft-code/go,linux-on-ibm-z/go,Endika/go,4ad/go,mwhudson/go,vsekhar/elastic-go,suncycheng/go,goodlang/good,golang/go,goodlang/good,roth1002/go,mwhudson/go,cloudflare/go,vanloswang/go,Samurais/go,Endika/go,fjballest/golang,odeke-em/go,roth1002/go,sndnvaps/go,miolini/go,Cofyc/go,polyverse-security/go,deft-code/go,akutz/go,vanloswang/go,cyberroadie/go,ganboing/go-esx,nawawi/go,codestation/go,mwhudson/go,roth1002/go,vanloswang/go,deft-code/go,sndnvaps/go,linux-on-ibm-z/go,derekmarcotte/go,akutz/go,vsekhar/elastic-go,Endika/go,CAFxX/go,kim-racktop/go,suncycheng/go,momchil-velikov/go,linux-on-ibm-z/go,Endika/go,fjballest/golang,roth1002/go,Cofyc/go,binarycrusader/go,binarycrusader/go,theif519/go,derekmarcotte/go,momchil-velikov/go,codestation/go,vsekhar/elastic-go,Cofyc/go,goodlang/good,4ad/go,cyberroadie/go,vsekhar/elastic-go,Endika/go,miolini/go,nawawi/go,golang/go,cloudflare/go,vanloswang/go,polyverse-security/go,sndnvaps/go,CAFxX/go,vanloswang/go,nawawi/go,CAFxX/go,vsekhar/elastic-go,odeke-em/go,momchil-velikov/go,Samurais/go,fjballest/golang,josharian/go,4ad/go,nawawi/go,Samurais/go,codestation/go,goodlang/good,Samurais/go,CAFxX/go,Cofyc/go,christopher-henderson/Go,Endika/go,linux-on-ibm-z/go,goodlang/good,fjballest/golang,sndnvaps/go,odeke-em/go,polyverse-security/go,miolini/go,sndnvaps/go,josharian/go,ImJasonH/go,CAFxX/go,roth1002/go,mwhudson/go,cloudflare/go,polyverse-security/go,derekmarcotte/go,akutz/go,ganboing/go-esx,akutz/go,suncycheng/go,cyberroadie/go,binarycrusader/go,Samurais/go,4ad/go,cyberroadie/go,mwhudson/go,fjballest/golang,theif519/go,odeke-em/go,vanloswang/go,josharian/go,fjballest/golang,golang/go,golang/go,golang/go,fjballest/golang,cyberroadie/go,miolini/go,mwhudson/go,kim-racktop/go,ImJasonH/go,deft-code/go,nawawi/go,deft-code/go,odeke-em/go,roth1002/go,Samurais/go,codestation/go,4ad/go,odeke-em/go,binarycrusader/go,momchil-velikov/go,4ad/go,CAFxX/go,codestation/go,roth1002/go,codestation/go,kim-racktop/go,derekmarcotte/go,ImJasonH/go,CAFxX/go,polyverse-security/go,binarycrusader/go,josharian/go,linux-on-ibm-z/go,miolini/go,momchil-velikov/go,vsekhar/elastic-go,goodlang/good,miolini/go,golang/go,odeke-em/go,vanloswang/go,cyberroadie/go,kim-racktop/go,miolini/go,josharian/go,Cofyc/go,binarycrusader/go,akutz/go,ganboing/go-esx,suncycheng/go,4ad/go,Cofyc/go,linux-on-ibm-z/go,linux-on-ibm-z/go,polyverse-security/go,sndnvaps/go,cloudflare/go,cyberroadie/go,kim-racktop/go,josharian/go,derekmarcotte/go,golang/go,ganboing/go-esx,ganboing/go-esx,polyverse-security/go,theif519/go,linux-on-ibm-z/go,4ad/go,nawawi/go,ImJasonH/go,Endika/go,Samurais/go,mwhudson/go,josharian/go,ganboing/go-esx,Endika/go