Logs how often users clear Omnibox.
Logs how often users clear Omnibox.

We're interested in the scenario that, a user wanted to use IME in Omnibox, but forgot to turn IME on, or opposite (wanted to not use IME, but forgot to turn IME off).  In these cases, most users realize their mistake just after typing a few characters, which are not what they expected, then delete all the text in Omnibox with backspace key (or escape key), turn IME on/off, and type again what they wanted to input.
We're interested in how often this scenario happens, and would like to see this frequency will reduce as we improve the Omnibox UX for IME users.

This CL adds a histogram named "Omnibox.UserTextCleared" which shows the number of times that users deleted all their input and the number of times that users hit escape key to revert their input.

BUG=172180
TEST=no regression

Review URL: https://chromiumcodereview.appspot.com/12211043

git-svn-id: de016e52bd170d2d4f2344f9bf92d50478b649e0@183058 0039d316-1c4b-4281-b951-d872f2087c98

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