Add missing identity variables to gypd generator.
Add missing identity variables to gypd generator.

Add variables set by default in other generators as identity variables
for gypd, to fix running gypd on chromium. This seems to bring the list
in line with the variables set by dump_dependency_json and ninja.

AWhetter/gyp,cysp/gyp,clar/gyp,chromium/gyp,msc-/gyp,ryfx/gyp,adblockplus/gyp,duanhjlt/gyp,carlTLR/gyp,AWhetter/gyp,tarc/gyp,dougbeal/gyp,duanhjlt/gyp,duanhjlt/gyp,yjhjstz/gyp,bulldy80/gyp_unofficial,ryfx/gyp,Danath/gyp,tarc/gyp,adblockplus/gyp,turbulenz/gyp,turbulenz/gyp,mgamer/gyp,bulldy80/gyp_unofficial,cysp/gyp,bnq4ever/gypgoogle,enkripsi/gyp,Danath/gyp,turbulenz/gyp,mgamer/gyp,yjhjstz/gyp,cchamberlain/gyp,bnq4ever/gypgoogle,pandaxcl/gyp,sdklite/gyp,enkripsi/gyp,LazyCodingCat/gyp,carlTLR/gyp,Jack-Q/GYP-copy,AWhetter/gyp,tarc/gyp,carlTLR/gyp,AWhetter/gyp,azunite/gyp,yjhjstz/gyp,cchamberlain/gyp,enkripsi/gyp,sdklite/gyp,turbulenz/gyp,azunite/gyp,dougbeal/gyp,Jack-Q/GYP-copy,duanhjlt/gyp,Jack-Q/GYP-copy,carlTLR/gyp,bulldy80/gyp_unofficial,azunite/gyp,azunite/gyp,adblockplus/gyp,bulldy80/gyp_unofficial,bnoordhuis/gyp,LazyCodingCat/gyp,clar/gyp,dougbeal/gyp,ttyangf/gyp,sanyaade-teachings/gyp,Jack-Q/GYP-copy,Phuehvk/gyp,carlTLR/gyp,ryfx/gyp,sdklite/gyp,mgamer/gyp,dougbeal/gyp,clar/gyp,pandaxcl/gyp,sdklite/gyp,sdklite/gyp,ttyangf/gyp,ttyangf/gyp,LazyCodingCat/gyp,LazyCodingCat/gyp,chromium/gyp,enkripsi/gyp,cchamberlain/gyp,amoikevin/gyp,bnoordhuis/gyp,Danath/gyp,cysp/gyp,bnoordhuis/gyp,Phuehvk/gyp,azunite/gyp,chromium/gyp,trafi/gyp,sanyaade-teachings/gyp,ttyangf/gyp,msc-/gyp,ryfx/gyp,sanyaade-teachings/gyp,amoikevin/gyp,Danath/gyp,tarc/gyp,Phuehvk/gyp,amoikevin/gyp,adblockplus/gyp,bnq4ever/gypgoogle,msc-/gyp,trafi/gyp,pandaxcl/gyp,Jack-Q/GYP-copy,yjhjstz/gyp,ttyangf/gyp,pandaxcl/gyp,cchamberlain/gyp,dougbeal/gyp,sanyaade-teachings/gyp,msc-/gyp,turbulenz/gyp,azunite/gyp_20150930,pandaxcl/gyp,bnq4ever/gypgoogle,bnoordhuis/gyp,azunite/gyp_20150930,mgamer/gyp,clar/gyp,msc-/gyp,duanhjlt/gyp,azunite/gyp_20150930,bulldy80/gyp_unofficial,chromium/gyp,chromium/gyp,Phuehvk/gyp,azunite/gyp_20150930,clar/gyp,cchamberlain/gyp,trafi/gyp,mgamer/gyp,cysp/gyp,tarc/gyp,trafi/gyp,azunite/gyp_20150930,AWhetter/gyp,adblockplus/gyp,ryfx/gyp,bnoordhuis/gyp,amoikevin/gyp,enkripsi/gyp,trafi/gyp,cysp/gyp,amoikevin/gyp,Phuehvk/gyp,bnq4ever/gypgoogle,Danath/gyp,LazyCodingCat/gyp,yjhjstz/gyp,sanyaade-teachings/gyp