Make generator: write a more efficient version of fixup_dep that is O(1) instead of O(n) for the number of exec()s, with n = number of dependencies. All those calls to xargs -n1 printf is slowing the build down because calls to fixup_dep is taking up a make job slot that would otherwise go towards g++.
Make generator: write a more efficient version of fixup_dep that is O(1) instead of O(n) for the number of exec()s, with n = number of dependencies. All those calls to xargs -n1 printf is slowing the build down because calls to fixup_dep is taking up a make job slot that would otherwise go towards g++.

BUG=http://code.google.com/p/gyp/issues/detail?id=140
TEST=Verify the .deps directory is the same for base_unittests. Verify base_unittests builds 5-10% faster on a quad core computer.
Review URL: http://codereview.chromium.org/1695006
witwall/gyp,witwall/gyp,witwall/gyp,witwall/gyp,witwall/gyp