Mac: Properly put the NSURLs on the pasteboard when dragging from web content.
Mac: Properly put the NSURLs on the pasteboard when dragging from web content.

Don't use the Mozilla code which (a) wasn't designed for lazy writes, and (b) is weird and kind of broken for file URLs.

BUG=29911
TEST=Should be able to drag images (from a local web page) to Finder. Other drag-and-drop functionality (from web content) should continue to work as before.

Review URL: http://codereview.chromium.org/1223005

git-svn-id: de016e52bd170d2d4f2344f9bf92d50478b649e0@42945 0039d316-1c4b-4281-b951-d872f2087c98

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