Enhance TestGyp classes to look for the build tool to use in tests from a list of possible choices.  Use this capability to search for either 'scons' or 'scons.py' in tests of the SCons generator. Review URL: http://codereview.chromium.org/173509
Enhance TestGyp classes to look for the build tool to use in tests
from a list of possible choices.  Use this capability to search
for either 'scons' or 'scons.py' in tests of the SCons generator.
Review URL: http://codereview.chromium.org/173509

git-svn-id: e7e1075985beda50ea81ac4472467b4f6e91fc78@608 78cadc50-ecff-11dd-a971-7dbc132099af

bulldy80/gyp_unofficial,lianliuwei/gyp,Omegaphora/external_chromium_org_tools_gyp,dougbeal/gyp,enkripsi/gyp,alexcrichton/gyp,xin3liang/platform_external_chromium_org_tools_gyp,mumble-voip/libmumble-gyp,duanhjlt/gyp,yinquan529/platform-external-chromium_org-tools-gyp,bulldy80/gyp_unofficial,cysp/gyp,android-ia/platform_external_chromium_org_tools_gyp,ttyangf/gyp,pyokagan/gyp,yjhjstz/gyp,azunite/gyp,MIPS/external-chromium_org-tools-gyp,turbulenz/gyp,bpsinc-native/src_tools_gyp,channing/gyp,IllusionRom-deprecated/android_platform_external_chromium_org_tools_gyp,mapbox/gyp,yangrongwei/gyp,ryfx/gyp,mistydemeo/gyp,bnoordhuis/gyp,ryfx/gyp,svn2github/gyp,okwasi/gyp,LazyCodingCat/gyp,lianliuwei/gyp,mumble-voip/libmumble-gyp,chromium/gyp,saghul/gyn,sfiera/gyp,xin3liang/platform_external_chromium_org_tools_gyp,azunite/gyp_20150930,sdklite/gyp,erikge/watch_gyp,pyokagan/gyp,xin3liang/platform_external_chromium_org_tools_gyp,alexcrichton/gyp,cchamberlain/gyp,trafi/gyp,cysp/gyp,saghul/gyn,sloanyang/gyp,luvit/gyp,bnoordhuis/gyp,kevinchen3315/gyp-git,Chilledheart/gyp,yinquan529/platform-external-chromium_org-tools-gyp,chromium/gyp,bnq4ever/gypgoogle,sfiera/gyp,turbulenz/gyp,erikge/watch_gyp,Phuehvk/gyp,pandaxcl/gyp,clar/gyp,cchamberlain/gyp,Jack-Q/GYP-copy,carlTLR/gyp,cchamberlain/gyp,AWhetter/gyp,bdarnell/gyp,Danath/gyp,carlTLR/gyp,ttyangf/pdfium_gyp,Phuehvk/gyp,LazyCodingCat/gyp,kevinchen3315/gyp-git,msc-/gyp,geekboxzone/lollipop_external_chromium_org_tools_gyp,MIPS/external-chromium_org-tools-gyp,Omegaphora/external_chromium_org_tools_gyp,mgamer/gyp,bnq4ever/gypgoogle,okwasi/gyp,enkripsi/gyp,adblockplus/gyp,MIPS/external-chromium_org-tools-gyp,enkripsi/gyp,svn2github/gyp,duanhjlt/gyp,brson/gyp,Danath/gyp,amoikevin/gyp,amoikevin/gyp,sdklite/gyp,bdarnell/gyp,omasanori/gyp,Omegaphora/external_chromium_org_tools_gyp,springmeyer/gyp,saghul/gyn,amoikevin/gyp,ttyangf/gyp,xin3liang/platform_external_chromium_org_tools_gyp,IllusionRom-deprecated/android_platform_external_chromium_org_tools_gyp,mistydemeo/gyp,sport-monkey/GYP,azunite/gyp_20150930,mgamer/gyp,msc-/gyp,cysp/gyp,geekboxzone/lollipop_external_chromium_org_tools_gyp,channing/gyp,bpsinc-native/src_tools_gyp,azunite/gyp,IllusionRom-deprecated/android_platform_external_chromium_org_tools_gyp,lukeweber/gyp-override,adblockplus/gyp,svn2github/gyp,android-ia/platform_external_chromium_org_tools_gyp,ttyangf/gyp,IllusionRom-deprecated/android_platform_external_chromium_org_tools_gyp,okwasi/gyp,springmeyer/gyp,kevinchen3315/gyp-git,mapbox/gyp,okumura/gyp,ryfx/gyp,dougbeal/gyp,AWhetter/gyp,clar/gyp,ryfx/gyp,msc-/gyp,mumble-voip/libmumble-gyp,sfiera/gyp,azunite/gyp,sloanyang/gyp,channing/gyp,bdarnell/gyp,turbulenz/gyp,pandaxcl/gyp,sport-monkey/GYP,yjhjstz/gyp,sanyaade-teachings/gyp,sloanyang/gyp,clar/gyp,amoikevin/gyp,chromium/gyp,msc-/gyp,erikge/watch_gyp,omasanori/gyp,geekboxzone/lollipop_external_chromium_org_tools_gyp,AOSPU/external_chromium_org_tools_gyp,msc-/gyp,cchamberlain/gyp,geekboxzone/lollipop_external_chromium_org_tools_gyp,duanhjlt/gyp,tarc/gyp,mistydemeo/gyp,LazyCodingCat/gyp,yjhjstz/gyp,sport-monkey/GYP,bnoordhuis/gyp,mgamer/gyp,yangrongwei/gyp,Jack-Q/GYP-copy,bpsinc-native/src_tools_gyp,springmeyer/gyp,cysp/gyp,svn2github/kgyp,trafi/gyp,svn2github/kgyp,openpeer/webrtc-gyp,AOSPU/external_chromium_org_tools_gyp,luvit/gyp,tarc/gyp,sdklite/gyp,mumble-voip/libmumble-gyp,ryfx/gyp,sport-monkey/GYP,openpeer/webrtc-gyp,mkrautz/gyp-libmumble,bpsinc-native/src_tools_gyp,springmeyer/gyp,okumura/gyp,Omegaphora/external_chromium_org_tools_gyp,alexcrichton/gyp,mistydemeo/gyp,svn2github/kgyp,sloanyang/gyp,yjhjstz/gyp,turbulenz/gyp,dougbeal/gyp,bulldy80/gyp_unofficial,duanhjlt/gyp,sdklite/gyp,Phuehvk/gyp,android-ia/platform_external_chromium_org_tools_gyp,turbulenz/gyp,azunite/gyp,pyokagan/gyp,trafi/gyp,yinquan529/platform-external-chromium_org-tools-gyp,LazyCodingCat/gyp,pandaxcl/gyp,Jack-Q/GYP-copy,mapbox/gyp,bnoordhuis/gyp,bnq4ever/gypgoogle,mapbox/gyp,bdarnell/gyp,carlTLR/gyp,azunite/gyp_20150930,svn2github/gyp,bulldy80/gyp_unofficial,trafi/gyp,alexcrichton/gyp,AWhetter/gyp,saghul/gyn,mgamer/gyp,Danath/gyp,springmeyer/gyp,brson/gyp,lukeweber/gyp-override,carlTLR/gyp,duanhjlt/gyp,AWhetter/gyp,erikge/watch_gyp,ttyangf/gyp,dougbeal/gyp,AWhetter/gyp,sanyaade-teachings/gyp,adblockplus/gyp,Phuehvk/gyp,cchamberlain/gyp,Chilledheart/gyp,Chilledheart/gyp,mgamer/gyp,sanyaade-teachings/gyp,azunite/gyp,brson/gyp,okwasi/gyp,okumura/gyp,lukeweber/gyp-override,Phuehvk/gyp,chromium/gyp,bnq4ever/gypgoogle,kevinchen3315/gyp-git,sanyaade-teachings/gyp,AOSPU/external_chromium_org_tools_gyp,bulldy80/gyp_unofficial,yinquan529/platform-external-chromium_org-tools-gyp,dougbeal/gyp,Jack-Q/GYP-copy,adblockplus/gyp,ttyangf/pdfium_gyp,mkrautz/gyp-libmumble,Danath/gyp,ttyangf/pdfium_gyp,tarc/gyp,LazyCodingCat/gyp,clar/gyp,lukeweber/gyp-override,svn2github/kgyp,yangrongwei/gyp,carlTLR/gyp,ttyangf/gyp,yjhjstz/gyp,pandaxcl/gyp,lianliuwei/gyp,Jack-Q/GYP-copy,tarc/gyp,trafi/gyp,sanyaade-teachings/gyp,yangrongwei/gyp,cysp/gyp,openpeer/webrtc-gyp,channing/gyp,chromium/gyp,erikge/watch_gyp,MIPS/external-chromium_org-tools-gyp,ttyangf/pdfium_gyp,Chilledheart/gyp,pandaxcl/gyp,ttyangf/pdfium_gyp,bnoordhuis/gyp,pyokagan/gyp,mapbox/gyp,azunite/gyp_20150930,amoikevin/gyp,okumura/gyp,mkrautz/gyp-libmumble,AOSPU/external_chromium_org_tools_gyp,Danath/gyp,enkripsi/gyp,mkrautz/gyp-libmumble,adblockplus/gyp,omasanori/gyp,openpeer/webrtc-gyp,omasanori/gyp,luvit/gyp,sdklite/gyp,svn2github/gyp,Chilledheart/gyp,brson/gyp,svn2github/kgyp,saghul/gyn,luvit/gyp,openpeer/webrtc-gyp,sport-monkey/GYP,bnq4ever/gypgoogle,pyokagan/gyp,clar/gyp,android-ia/platform_external_chromium_org_tools_gyp,azunite/gyp_20150930,enkripsi/gyp,tarc/gyp,lianliuwei/gyp