Allow loading multiple plug-ins with the same base name on Mac.
Allow loading multiple plug-ins with the same base name on Mac.

The rationale for not allowing it was to let plug-ins from higher in the hierarchy (i.e. ~/Library/Internet Plugins) override plug-ins from deeper (i.e. /Library/Internet Plugins), but loading them earlier already takes care of that.

BUG=132894
TEST=see bug for manual test


Review URL: https://chromiumcodereview.appspot.com/10555003

git-svn-id: de016e52bd170d2d4f2344f9bf92d50478b649e0@142723 0039d316-1c4b-4281-b951-d872f2087c98

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