Fix subpages closing on clicking radio/checkbox span problem.
Fix subpages closing on clicking radio/checkbox span problem.

Clicking on a radio/checkbox label span on a subpage closes it. Clicking
on a label span generates a click event for its target input and that
generated event has (0,0) as its client coordinates. This breaks our
subpage close logic.

BUG=chromium-os:12679
TEST=Verify fix for chromium-os:12679.

Review URL: http://codereview.chromium.org/6652001

git-svn-id: de016e52bd170d2d4f2344f9bf92d50478b649e0@77347 0039d316-1c4b-4281-b951-d872f2087c98

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