Correct error reporting in run-bindings-tests
Correct error reporting in run-bindings-tests

Currently run-bindings-tests:
* has dead code (diff results in exception, so checking output never hit)
* has redundant code (always want to print output of commands)
* ...and lacks clear distinction of script errors vs. diffs

This arose b/c I noticed that I never saw the 'FAIL' line, as that was
dead code.

This fixes these problems.

Review URL: https://codereview.chromium.org/73513003

git-svn-id: bf5cd6ccde378db821296732a091cfbcf5285fbd@162109 bbb929c8-8fbe-4397-9dbb-9b2b20218538

Bysmyyr/blink-crosswalk,ondra-novak/blink,XiaosongWei/blink-crosswalk,XiaosongWei/blink-crosswalk,PeterWangIntel/blink-crosswalk,jtg-gg/blink,jtg-gg/blink,kurli/blink-crosswalk,Pluto-tv/blink-crosswalk,kurli/blink-crosswalk,nwjs/blink,PeterWangIntel/blink-crosswalk,crosswalk-project/blink-crosswalk-efl,jtg-gg/blink,nwjs/blink,ondra-novak/blink,XiaosongWei/blink-crosswalk,nwjs/blink,Pluto-tv/blink-crosswalk,smishenk/blink-crosswalk,modulexcite/blink,Bysmyyr/blink-crosswalk,Bysmyyr/blink-crosswalk,nwjs/blink,modulexcite/blink,smishenk/blink-crosswalk,hgl888/blink-crosswalk-efl,XiaosongWei/blink-crosswalk,modulexcite/blink,XiaosongWei/blink-crosswalk,crosswalk-project/blink-crosswalk-efl,kurli/blink-crosswalk,modulexcite/blink,hgl888/blink-crosswalk-efl,nwjs/blink,Pluto-tv/blink-crosswalk,PeterWangIntel/blink-crosswalk,hgl888/blink-crosswalk-efl,PeterWangIntel/blink-crosswalk,ondra-novak/blink,Pluto-tv/blink-crosswalk,modulexcite/blink,crosswalk-project/blink-crosswalk-efl,crosswalk-project/blink-crosswalk-efl,jtg-gg/blink,hgl888/blink-crosswalk-efl,XiaosongWei/blink-crosswalk,Bysmyyr/blink-crosswalk,kurli/blink-crosswalk,modulexcite/blink,nwjs/blink,Pluto-tv/blink-crosswalk,kurli/blink-crosswalk,crosswalk-project/blink-crosswalk-efl,ondra-novak/blink,kurli/blink-crosswalk,modulexcite/blink,nwjs/blink,smishenk/blink-crosswalk,nwjs/blink,PeterWangIntel/blink-crosswalk,jtg-gg/blink,ondra-novak/blink,hgl888/blink-crosswalk-efl,jtg-gg/blink,crosswalk-project/blink-crosswalk-efl,kurli/blink-crosswalk,Pluto-tv/blink-crosswalk,PeterWangIntel/blink-crosswalk,nwjs/blink,Bysmyyr/blink-crosswalk,Bysmyyr/blink-crosswalk,PeterWangIntel/blink-crosswalk,kurli/blink-crosswalk,modulexcite/blink,nwjs/blink,PeterWangIntel/blink-crosswalk,Bysmyyr/blink-crosswalk,jtg-gg/blink,smishenk/blink-crosswalk,smishenk/blink-crosswalk,PeterWangIntel/blink-crosswalk,ondra-novak/blink,smishenk/blink-crosswalk,smishenk/blink-crosswalk,jtg-gg/blink,PeterWangIntel/blink-crosswalk,Pluto-tv/blink-crosswalk,XiaosongWei/blink-crosswalk,hgl888/blink-crosswalk-efl,smishenk/blink-crosswalk,modulexcite/blink,XiaosongWei/blink-crosswalk,Bysmyyr/blink-crosswalk,jtg-gg/blink,crosswalk-project/blink-crosswalk-efl,ondra-novak/blink,ondra-novak/blink,hgl888/blink-crosswalk-efl,hgl888/blink-crosswalk-efl,kurli/blink-crosswalk,Pluto-tv/blink-crosswalk,crosswalk-project/blink-crosswalk-efl,smishenk/blink-crosswalk,modulexcite/blink,XiaosongWei/blink-crosswalk,kurli/blink-crosswalk,hgl888/blink-crosswalk-efl,hgl888/blink-crosswalk-efl,Pluto-tv/blink-crosswalk,smishenk/blink-crosswalk,Bysmyyr/blink-crosswalk,Bysmyyr/blink-crosswalk,crosswalk-project/blink-crosswalk-efl,jtg-gg/blink,XiaosongWei/blink-crosswalk,ondra-novak/blink,Pluto-tv/blink-crosswalk