CpuProfiler: eliminate 2 layers of 4 for CodeCreateEvent calls.

The bodies of methods in ProfilerEventProcessor were moved into CpuProfiler.
Multiple NewCodeEntry methods in CpuProfilesCollection were replaced with one which
simply passes arguments to the CodeEntry constructor.
And CpuProfiler just calls this method when it needs a CodeEntry object.

This NewCodeEntry method is required because CpuProfilesCollection keeps ownership of CodeEntry objects.

BUG=255392
TEST=existing tests
R=yangguo@chromium.org, yurys@chromium.org

Review URL: https://codereview.chromium.org/18053004

git-svn-id: https://v8.googlecode.com/svn/branches/bleeding_edge@15405 ce2b1a6d-e550-0410-aec6-3dcde31c8c00