CPU profiler: increase the max number of captured frames.

LOG=N
R=jkummerow@chromium.org, loislo@chromium.org, yurys@chromium.org

Review URL: https://codereview.chromium.org/357443003

git-svn-id: https://v8.googlecode.com/svn/branches/bleeding_edge@21986 ce2b1a6d-e550-0410-aec6-3dcde31c8c00