views: Implement NativeTableGtk::RemoveColumn method.
views: Implement NativeTableGtk::RemoveColumn method.

Also fix the following error when we try to get the width of column that does not exist anymore.

(views_examples:3921): Gtk-CRITICAL **: gtk_tree_view_column_get_width: assertion `GTK_IS_TREE_VIEW_COLUMN (tree_column)' failed

BUG=None
TEST=export GYP_DEFINES="toolkit_views" && gclient runhooks && make -j4 -k views_examples
     out/Debug/views_examples, go to the table tab. Now clicking in one of the checkboxes,
     the corresponded column should be removed.

Review URL: http://codereview.chromium.org/6256004

git-svn-id: de016e52bd170d2d4f2344f9bf92d50478b649e0@71786 0039d316-1c4b-4281-b951-d872f2087c98

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