This significantly reduces amount of files to be recompiled after changes in cpu-profiler.h and its dependencies.

BUG=None
R=loislo@chromium.org, yangguo@chromium.org

Review URL: https://codereview.chromium.org/18522004

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@15482 ce2b1a6d-e550-0410-aec6-3dcde31c8c00