Refer to build/mac/find_sdk.py in a more robust way.
Refer to build/mac/find_sdk.py in a more robust way.

This broke the WebKit Mac bot, as the directory it works in is different there
compared to the Chromium configuration. Determine the source's root through the
DEPTH define, and then walk up in the build/mac/ directory.

BUG=
TEST=WebKit Mac builder doesn't break after a Chromium DEPS roll.


Review URL: https://chromiumcodereview.appspot.com/10824105

git-svn-id: de016e52bd170d2d4f2344f9bf92d50478b649e0@149181 0039d316-1c4b-4281-b951-d872f2087c98

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