This fixes a regression introduced by my fix for http://code.google.com/p/chromium/issues/detail?id=2846 (Revision 3262).
This fixes a regression introduced by my fix for http://code.google.com/p/chromium/issues/detail?id=2846 (Revision 3262).

The one to one mapping between mime types and supported extensions, which 
enables us to look up a plugin based on a URL extension regressed as a result
of the above change.

R=jam


Review URL: http://codereview.chromium.org/7272

git-svn-id: de016e52bd170d2d4f2344f9bf92d50478b649e0@3300 0039d316-1c4b-4281-b951-d872f2087c98

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