linux: work around "flash does not register any clicks" bug
linux: work around "flash does not register any clicks" bug

I had a flash of inspiration!  Setting GDK_NATIVE_WINDOWS in the
environment doesn't work because we don't propagate the setting down
into the plugin subprocess.  I confirmed that setting it manually
fixes it.  That is, on this computer I previously had the no-clicks
bug and with this change the problem is solved.

Note: there are multiple confusing levels to this bug; if
nspluginwrapper gets involved I still encounter the problem.
But this definitely fixes the problem for me.

BUG=20654

Review URL: http://codereview.chromium.org/384059

git-svn-id: de016e52bd170d2d4f2344f9bf92d50478b649e0@31734 0039d316-1c4b-4281-b951-d872f2087c98

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