Avoid spinning the UI loop in WidgetTest.ExitFullscreenRestoreState
Avoid spinning the UI loop in WidgetTest.ExitFullscreenRestoreState

Otherwise a failure can result in an infinite loop and stdio spew that
clogs the test runner.

This also helps ensure maximize and fullscreen states read back via the
widget are updated synchronously. This behaviour is assumed for the
correct operation, e.g., of NativeAppWindowViews and packaged app APIs.

Bot runs and local tests with --gtest_repeat suggest that this does not
inadvertently introduce flakiness.

BUG=378134

Review URL: https://codereview.chromium.org/321353003

git-svn-id: de016e52bd170d2d4f2344f9bf92d50478b649e0@277578 0039d316-1c4b-4281-b951-d872f2087c98

jaruba/chromium.src,markYoungH/chromium.src,M4sse/chromium.src,Pluto-tv/chromium-crosswalk,Chilledheart/chromium,PeterWangIntel/chromium-crosswalk,Chilledheart/chromium,crosswalk-project/chromium-crosswalk-efl,chuan9/chromium-crosswalk,bright-sparks/chromium-spacewalk,crosswalk-project/chromium-crosswalk-efl,Just-D/chromium-1,markYoungH/chromium.src,fujunwei/chromium-crosswalk,crosswalk-project/chromium-crosswalk-efl,axinging/chromium-crosswalk,Jonekee/chromium.src,dednal/chromium.src,ltilve/chromium,axinging/chromium-crosswalk,krieger-od/nwjs_chromium.src,hgl888/chromium-crosswalk-efl,M4sse/chromium.src,hgl888/chromium-crosswalk,bright-sparks/chromium-spacewalk,hgl888/chromium-crosswalk-efl,Jonekee/chromium.src,Fireblend/chromium-crosswalk,Pluto-tv/chromium-crosswalk,chuan9/chromium-crosswalk,M4sse/chromium.src,PeterWangIntel/chromium-crosswalk,markYoungH/chromium.src,axinging/chromium-crosswalk,markYoungH/chromium.src,PeterWangIntel/chromium-crosswalk,Just-D/chromium-1,Jonekee/chromium.src,M4sse/chromium.src,hgl888/chromium-crosswalk-efl,ondra-novak/chromium.src,ondra-novak/chromium.src,Jonekee/chromium.src,fujunwei/chromium-crosswalk,Just-D/chromium-1,axinging/chromium-crosswalk,mohamed--abdel-maksoud/chromium.src,dushu1203/chromium.src,M4sse/chromium.src,fujunwei/chromium-crosswalk,markYoungH/chromium.src,Fireblend/chromium-crosswalk,krieger-od/nwjs_chromium.src,hgl888/chromium-crosswalk-efl,hgl888/chromium-crosswalk-efl,dushu1203/chromium.src,Fireblend/chromium-crosswalk,littlstar/chromium.src,ondra-novak/chromium.src,bright-sparks/chromium-spacewalk,TheTypoMaster/chromium-crosswalk,krieger-od/nwjs_chromium.src,mohamed--abdel-maksoud/chromium.src,mohamed--abdel-maksoud/chromium.src,markYoungH/chromium.src,Jonekee/chromium.src,M4sse/chromium.src,Just-D/chromium-1,Just-D/chromium-1,markYoungH/chromium.src,Just-D/chromium-1,krieger-od/nwjs_chromium.src,TheTypoMaster/chromium-crosswalk,M4sse/chromium.src,Chilledheart/chromium,littlstar/chromium.src,hgl888/chromium-crosswalk,dednal/chromium.src,Just-D/chromium-1,mohamed--abdel-maksoud/chromium.src,littlstar/chromium.src,ltilve/chromium,PeterWangIntel/chromium-crosswalk,Chilledheart/chromium,axinging/chromium-crosswalk,PeterWangIntel/chromium-crosswalk,Pluto-tv/chromium-crosswalk,Pluto-tv/chromium-crosswalk,TheTypoMaster/chromium-crosswalk,PeterWangIntel/chromium-crosswalk,littlstar/chromium.src,dednal/chromium.src,krieger-od/nwjs_chromium.src,mohamed--abdel-maksoud/chromium.src,Jonekee/chromium.src,ltilve/chromium,krieger-od/nwjs_chromium.src,mohamed--abdel-maksoud/chromium.src,crosswalk-project/chromium-crosswalk-efl,TheTypoMaster/chromium-crosswalk,Fireblend/chromium-crosswalk,Jonekee/chromium.src,chuan9/chromium-crosswalk,hgl888/chromium-crosswalk-efl,chuan9/chromium-crosswalk,ondra-novak/chromium.src,ondra-novak/chromium.src,hgl888/chromium-crosswalk,bright-sparks/chromium-spacewalk,hgl888/chromium-crosswalk,Just-D/chromium-1,axinging/chromium-crosswalk,dushu1203/chromium.src,ltilve/chromium,hgl888/chromium-crosswalk-efl,dushu1203/chromium.src,dednal/chromium.src,littlstar/chromium.src,PeterWangIntel/chromium-crosswalk,hgl888/chromium-crosswalk-efl,bright-sparks/chromium-spacewalk,crosswalk-project/chromium-crosswalk-efl,M4sse/chromium.src,dushu1203/chromium.src,krieger-od/nwjs_chromium.src,Pluto-tv/chromium-crosswalk,TheTypoMaster/chromium-crosswalk,hgl888/chromium-crosswalk-efl,M4sse/chromium.src,dushu1203/chromium.src,crosswalk-project/chromium-crosswalk-efl,bright-sparks/chromium-spacewalk,Pluto-tv/chromium-crosswalk,littlstar/chromium.src,fujunwei/chromium-crosswalk,fujunwei/chromium-crosswalk,ondra-novak/chromium.src,dednal/chromium.src,dushu1203/chromium.src,axinging/chromium-crosswalk,crosswalk-project/chromium-crosswalk-efl,jaruba/chromium.src,dushu1203/chromium.src,hgl888/chromium-crosswalk,bright-sparks/chromium-spacewalk,Fireblend/chromium-crosswalk,markYoungH/chromium.src,axinging/chromium-crosswalk,bright-sparks/chromium-spacewalk,hgl888/chromium-crosswalk,dushu1203/chromium.src,TheTypoMaster/chromium-crosswalk,mohamed--abdel-maksoud/chromium.src,hgl888/chromium-crosswalk-efl,dednal/chromium.src,chuan9/chromium-crosswalk,krieger-od/nwjs_chromium.src,dushu1203/chromium.src,krieger-od/nwjs_chromium.src,dednal/chromium.src,Chilledheart/chromium,Pluto-tv/chromium-crosswalk,ltilve/chromium,Chilledheart/chromium,chuan9/chromium-crosswalk,axinging/chromium-crosswalk,jaruba/chromium.src,fujunwei/chromium-crosswalk,hgl888/chromium-crosswalk,markYoungH/chromium.src,jaruba/chromium.src,littlstar/chromium.src,dednal/chromium.src,Chilledheart/chromium,TheTypoMaster/chromium-crosswalk,crosswalk-project/chromium-crosswalk-efl,jaruba/chromium.src,fujunwei/chromium-crosswalk,ondra-novak/chromium.src,axinging/chromium-crosswalk,fujunwei/chromium-crosswalk,crosswalk-project/chromium-crosswalk-efl,Chilledheart/chromium,dednal/chromium.src,krieger-od/nwjs_chromium.src,hgl888/chromium-crosswalk,dednal/chromium.src,M4sse/chromium.src,jaruba/chromium.src,Jonekee/chromium.src,ltilve/chromium,axinging/chromium-crosswalk,littlstar/chromium.src,TheTypoMaster/chromium-crosswalk,chuan9/chromium-crosswalk,dednal/chromium.src,ondra-novak/chromium.src,mohamed--abdel-maksoud/chromium.src,fujunwei/chromium-crosswalk,M4sse/chromium.src,bright-sparks/chromium-spacewalk,PeterWangIntel/chromium-crosswalk,ltilve/chromium,jaruba/chromium.src,markYoungH/chromium.src,markYoungH/chromium.src,Fireblend/chromium-crosswalk,mohamed--abdel-maksoud/chromium.src,Just-D/chromium-1,TheTypoMaster/chromium-crosswalk,jaruba/chromium.src,Pluto-tv/chromium-crosswalk,jaruba/chromium.src,mohamed--abdel-maksoud/chromium.src,dushu1203/chromium.src,mohamed--abdel-maksoud/chromium.src,ltilve/chromium,chuan9/chromium-crosswalk,ltilve/chromium,ondra-novak/chromium.src,jaruba/chromium.src,Fireblend/chromium-crosswalk,krieger-od/nwjs_chromium.src,Jonekee/chromium.src,jaruba/chromium.src,Chilledheart/chromium,Fireblend/chromium-crosswalk,Pluto-tv/chromium-crosswalk,Fireblend/chromium-crosswalk,chuan9/chromium-crosswalk,Jonekee/chromium.src,Jonekee/chromium.src,PeterWangIntel/chromium-crosswalk,hgl888/chromium-crosswalk