Explicit includes of common.gypi are being deprecated.  Chromium will include
the .gypi files that it needs by asking GYP to force-include them into each
.gyp file that it loads.  See http://codereview.chromium.org/206006.
Review URL: http://codereview.chromium.org/193114

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@2895 ce2b1a6d-e550-0410-aec6-3dcde31c8c00