Remove 'shell=True' in Popen and directly execute testserver.py
Remove 'shell=True' in Popen and directly execute testserver.py

In chrome_test_server_spawner.py, testserver process is created by
'subprocess.Popen(command, shell=True)', it will create 2 processes(http://goo.gl/oDYsn):
  (1) /bin/sh -c testserver.py ...
  (2) python testserver.py ...
but subprocess.Popen only returns the 1st process(pid), so when kill testserver with
Popen.kill(), only the 1st process is killed, the 2nd process(testserver) still
remains there.

This leads to two problems:
 (1) testserver failed to be killed for each case with the log:
     '"GET /kill HTTP/1.1" 500'
 (2) many teserver processes are there after each run, and the port is used,
     when starting a new run, will get the following error:
	 'socket.error: [Errno 98] Address already in use'

Remove the 'shell=True' and fix this issue.

BUG=
TEST=net_unittests_apk --gtest_filter=URLRequestTestHTTP.*

Review URL: https://chromiumcodereview.appspot.com/10960050

git-svn-id: de016e52bd170d2d4f2344f9bf92d50478b649e0@158267 0039d316-1c4b-4281-b951-d872f2087c98

ChromiumWebApps/chromium,chuan9/chromium-crosswalk,chuan9/chromium-crosswalk,crosswalk-project/chromium-crosswalk-efl,dushu1203/chromium.src,pozdnyakov/chromium-crosswalk,pozdnyakov/chromium-crosswalk,krieger-od/nwjs_chromium.src,M4sse/chromium.src,ChromiumWebApps/chromium,crosswalk-project/chromium-crosswalk-efl,ltilve/chromium,Fireblend/chromium-crosswalk,jaruba/chromium.src,M4sse/chromium.src,ondra-novak/chromium.src,patrickm/chromium.src,dushu1203/chromium.src,littlstar/chromium.src,bright-sparks/chromium-spacewalk,anirudhSK/chromium,jaruba/chromium.src,markYoungH/chromium.src,hgl888/chromium-crosswalk-efl,hujiajie/pa-chromium,timopulkkinen/BubbleFish,M4sse/chromium.src,bright-sparks/chromium-spacewalk,Jonekee/chromium.src,nacl-webkit/chrome_deps,bright-sparks/chromium-spacewalk,mogoweb/chromium-crosswalk,ltilve/chromium,mohamed--abdel-maksoud/chromium.src,hgl888/chromium-crosswalk-efl,markYoungH/chromium.src,hgl888/chromium-crosswalk-efl,ltilve/chromium,pozdnyakov/chromium-crosswalk,Fireblend/chromium-crosswalk,Pluto-tv/chromium-crosswalk,mogoweb/chromium-crosswalk,Pluto-tv/chromium-crosswalk,pozdnyakov/chromium-crosswalk,mohamed--abdel-maksoud/chromium.src,timopulkkinen/BubbleFish,littlstar/chromium.src,krieger-od/nwjs_chromium.src,pozdnyakov/chromium-crosswalk,jaruba/chromium.src,zcbenz/cefode-chromium,patrickm/chromium.src,mogoweb/chromium-crosswalk,junmin-zhu/chromium-rivertrail,nacl-webkit/chrome_deps,anirudhSK/chromium,zcbenz/cefode-chromium,crosswalk-project/chromium-crosswalk-efl,PeterWangIntel/chromium-crosswalk,axinging/chromium-crosswalk,Jonekee/chromium.src,Just-D/chromium-1,markYoungH/chromium.src,ChromiumWebApps/chromium,crosswalk-project/chromium-crosswalk-efl,anirudhSK/chromium,ChromiumWebApps/chromium,dednal/chromium.src,ondra-novak/chromium.src,littlstar/chromium.src,krieger-od/nwjs_chromium.src,ChromiumWebApps/chromium,hgl888/chromium-crosswalk-efl,anirudhSK/chromium,zcbenz/cefode-chromium,chuan9/chromium-crosswalk,M4sse/chromium.src,mohamed--abdel-maksoud/chromium.src,ondra-novak/chromium.src,bright-sparks/chromium-spacewalk,dushu1203/chromium.src,Chilledheart/chromium,timopulkkinen/BubbleFish,patrickm/chromium.src,mohamed--abdel-maksoud/chromium.src,markYoungH/chromium.src,anirudhSK/chromium,ltilve/chromium,nacl-webkit/chrome_deps,krieger-od/nwjs_chromium.src,hgl888/chromium-crosswalk,Fireblend/chromium-crosswalk,M4sse/chromium.src,M4sse/chromium.src,hujiajie/pa-chromium,anirudhSK/chromium,TheTypoMaster/chromium-crosswalk,M4sse/chromium.src,fujunwei/chromium-crosswalk,hgl888/chromium-crosswalk,jaruba/chromium.src,zcbenz/cefode-chromium,mogoweb/chromium-crosswalk,TheTypoMaster/chromium-crosswalk,fujunwei/chromium-crosswalk,dednal/chromium.src,PeterWangIntel/chromium-crosswalk,hgl888/chromium-crosswalk-efl,dushu1203/chromium.src,fujunwei/chromium-crosswalk,timopulkkinen/BubbleFish,Chilledheart/chromium,junmin-zhu/chromium-rivertrail,fujunwei/chromium-crosswalk,crosswalk-project/chromium-crosswalk-efl,bright-sparks/chromium-spacewalk,dednal/chromium.src,pozdnyakov/chromium-crosswalk,mogoweb/chromium-crosswalk,anirudhSK/chromium,Just-D/chromium-1,ondra-novak/chromium.src,anirudhSK/chromium,hgl888/chromium-crosswalk-efl,ChromiumWebApps/chromium,dednal/chromium.src,krieger-od/nwjs_chromium.src,axinging/chromium-crosswalk,timopulkkinen/BubbleFish,fujunwei/chromium-crosswalk,Jonekee/chromium.src,nacl-webkit/chrome_deps,junmin-zhu/chromium-rivertrail,M4sse/chromium.src,ChromiumWebApps/chromium,timopulkkinen/BubbleFish,hgl888/chromium-crosswalk-efl,Just-D/chromium-1,hgl888/chromium-crosswalk,hgl888/chromium-crosswalk,ondra-novak/chromium.src,Pluto-tv/chromium-crosswalk,M4sse/chromium.src,nacl-webkit/chrome_deps,Jonekee/chromium.src,axinging/chromium-crosswalk,Just-D/chromium-1,ondra-novak/chromium.src,krieger-od/nwjs_chromium.src,PeterWangIntel/chromium-crosswalk,ltilve/chromium,Just-D/chromium-1,hujiajie/pa-chromium,axinging/chromium-crosswalk,axinging/chromium-crosswalk,nacl-webkit/chrome_deps,crosswalk-project/chromium-crosswalk-efl,ChromiumWebApps/chromium,dushu1203/chromium.src,TheTypoMaster/chromium-crosswalk,krieger-od/nwjs_chromium.src,bright-sparks/chromium-spacewalk,patrickm/chromium.src,Jonekee/chromium.src,bright-sparks/chromium-spacewalk,dushu1203/chromium.src,junmin-zhu/chromium-rivertrail,dednal/chromium.src,Chilledheart/chromium,littlstar/chromium.src,hujiajie/pa-chromium,chuan9/chromium-crosswalk,junmin-zhu/chromium-rivertrail,ltilve/chromium,junmin-zhu/chromium-rivertrail,PeterWangIntel/chromium-crosswalk,axinging/chromium-crosswalk,Pluto-tv/chromium-crosswalk,dednal/chromium.src,ChromiumWebApps/chromium,chuan9/chromium-crosswalk,axinging/chromium-crosswalk,Chilledheart/chromium,ltilve/chromium,ChromiumWebApps/chromium,crosswalk-project/chromium-crosswalk-efl,markYoungH/chromium.src,timopulkkinen/BubbleFish,Chilledheart/chromium,jaruba/chromium.src,nacl-webkit/chrome_deps,hgl888/chromium-crosswalk,krieger-od/nwjs_chromium.src,hgl888/chromium-crosswalk-efl,TheTypoMaster/chromium-crosswalk,markYoungH/chromium.src,hgl888/chromium-crosswalk-efl,mogoweb/chromium-crosswalk,krieger-od/nwjs_chromium.src,mohamed--abdel-maksoud/chromium.src,axinging/chromium-crosswalk,junmin-zhu/chromium-rivertrail,patrickm/chromium.src,Pluto-tv/chromium-crosswalk,mohamed--abdel-maksoud/chromium.src,Fireblend/chromium-crosswalk,jaruba/chromium.src,PeterWangIntel/chromium-crosswalk,anirudhSK/chromium,Just-D/chromium-1,hgl888/chromium-crosswalk,hujiajie/pa-chromium,zcbenz/cefode-chromium,patrickm/chromium.src,dushu1203/chromium.src,timopulkkinen/BubbleFish,hgl888/chromium-crosswalk,dushu1203/chromium.src,anirudhSK/chromium,pozdnyakov/chromium-crosswalk,markYoungH/chromium.src,Fireblend/chromium-crosswalk,junmin-zhu/chromium-rivertrail,Just-D/chromium-1,bright-sparks/chromium-spacewalk,littlstar/chromium.src,M4sse/chromium.src,krieger-od/nwjs_chromium.src,timopulkkinen/BubbleFish,ltilve/chromium,M4sse/chromium.src,crosswalk-project/chromium-crosswalk-efl,axinging/chromium-crosswalk,mohamed--abdel-maksoud/chromium.src,Fireblend/chromium-crosswalk,mogoweb/chromium-crosswalk,mohamed--abdel-maksoud/chromium.src,crosswalk-project/chromium-crosswalk-efl,dushu1203/chromium.src,ChromiumWebApps/chromium,mohamed--abdel-maksoud/chromium.src,TheTypoMaster/chromium-crosswalk,littlstar/chromium.src,littlstar/chromium.src,junmin-zhu/chromium-rivertrail,zcbenz/cefode-chromium,hgl888/chromium-crosswalk-efl,PeterWangIntel/chromium-crosswalk,timopulkkinen/BubbleFish,zcbenz/cefode-chromium,jaruba/chromium.src,Chilledheart/chromium,nacl-webkit/chrome_deps,Chilledheart/chromium,littlstar/chromium.src,dednal/chromium.src,hgl888/chromium-crosswalk,hujiajie/pa-chromium,Just-D/chromium-1,pozdnyakov/chromium-crosswalk,dushu1203/chromium.src,pozdnyakov/chromium-crosswalk,ltilve/chromium,markYoungH/chromium.src,Jonekee/chromium.src,chuan9/chromium-crosswalk,patrickm/chromium.src,fujunwei/chromium-crosswalk,Jonekee/chromium.src,axinging/chromium-crosswalk,jaruba/chromium.src,TheTypoMaster/chromium-crosswalk,PeterWangIntel/chromium-crosswalk,junmin-zhu/chromium-rivertrail,ondra-novak/chromium.src,ChromiumWebApps/chromium,nacl-webkit/chrome_deps,chuan9/chromium-crosswalk,TheTypoMaster/chromium-crosswalk,zcbenz/cefode-chromium,PeterWangIntel/chromium-crosswalk,timopulkkinen/BubbleFish,TheTypoMaster/chromium-crosswalk,jaruba/chromium.src,markYoungH/chromium.src,fujunwei/chromium-crosswalk,Just-D/chromium-1,dednal/chromium.src,pozdnyakov/chromium-crosswalk,mogoweb/chromium-crosswalk,chuan9/chromium-crosswalk,Pluto-tv/chromium-crosswalk,Jonekee/chromium.src,jaruba/chromium.src,Jonekee/chromium.src,Fireblend/chromium-crosswalk,mohamed--abdel-maksoud/chromium.src,Chilledheart/chromium,mohamed--abdel-maksoud/chromium.src,Fireblend/chromium-crosswalk,junmin-zhu/chromium-rivertrail,Chilledheart/chromium,jaruba/chromium.src,zcbenz/cefode-chromium,bright-sparks/chromium-spacewalk,zcbenz/cefode-chromium,pozdnyakov/chromium-crosswalk,hujiajie/pa-chromium,mogoweb/chromium-crosswalk,chuan9/chromium-crosswalk,nacl-webkit/chrome_deps,hgl888/chromium-crosswalk,Pluto-tv/chromium-crosswalk,dednal/chromium.src,hujiajie/pa-chromium,TheTypoMaster/chromium-crosswalk,fujunwei/chromium-crosswalk,Jonekee/chromium.src,dednal/chromium.src,hujiajie/pa-chromium,patrickm/chromium.src,axinging/chromium-crosswalk,dushu1203/chromium.src,ondra-novak/chromium.src,markYoungH/chromium.src,PeterWangIntel/chromium-crosswalk,zcbenz/cefode-chromium,nacl-webkit/chrome_deps,krieger-od/nwjs_chromium.src,mogoweb/chromium-crosswalk,anirudhSK/chromium,markYoungH/chromium.src,Pluto-tv/chromium-crosswalk,fujunwei/chromium-crosswalk,hujiajie/pa-chromium,Pluto-tv/chromium-crosswalk,Jonekee/chromium.src,patrickm/chromium.src,Fireblend/chromium-crosswalk,dednal/chromium.src,anirudhSK/chromium,hujiajie/pa-chromium,ondra-novak/chromium.src