Introduce PassRefPtr::AdoptRefTag and use it in the adoption constructor
Introduce PassRefPtr::AdoptRefTag and use it in the adoption constructor

Introduce PassRefPtr::AdoptRefTag and use it in the adoption constructor instead of bool argument.
Rationals:
- makes code more consistent, since having this kind of tags is a pattern in blink
- makes code more clear: it does not have an explanation comment any more.

Review URL: https://codereview.chromium.org/70383008

git-svn-id: bf5cd6ccde378db821296732a091cfbcf5285fbd@162123 bbb929c8-8fbe-4397-9dbb-9b2b20218538

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