Set PYTHON_PATH at TestServer Init() instead of Start()
Set PYTHON_PATH at TestServer Init() instead of Start()

Try to look up python paths at Init() time.  It's likely that some paths
in PathService will be overridden later, so if we do not succeed now
we'll try again upon Start().  This is necessary on Chromium OS, as we don't keep the tests next to the browser binary, and InProcessBrowserTest overrides FILE_EXE to point to the browser binary, confusing the test server :-/

BUG=66833
TEST=run browser tests, run chrome os browser test autotest, run ui tests

Review URL: http://codereview.chromium.org/5743008

git-svn-id: de016e52bd170d2d4f2344f9bf92d50478b649e0@70392 0039d316-1c4b-4281-b951-d872f2087c98

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