Make counter and histogram related callbacks part of the Isolate::CreateParams.

Make counter and histogram related callbacks part of the Isolate::CreateParams.

Some native counters (e.g. KeyedLoadGenericSlow) are referenced from stubs that are generated very early in the Isolate lifecycle before v8::Isolate::New returns. Thus counter lookup callback also needs to be installed early prior to v8::internal::Isolate::Init call. Otherwise assembler will just assume that the counter is not enabled and produce no code from IncrementCounter - because address of the counter is not yet available.

Histogram related callbacks are moved for consistency to make them able to collect samples which occur at isolate initialization time.

BUG=

Committed: https://crrev.com/0e024449b8322f99534c1901ac6acc6611ddcb1d
Cr-Commit-Position: refs/heads/master@{#27262}

[Vyacheslav Egorov (Google), 2015-03-17 16:38:32]

vegorov@google.com changed reviewers:
+ jkummerow@chromium.org

[Vyacheslav Egorov (Google), 2015-03-17 16:38:32]

Please take a look. I was trying to use counters to debug a performance issue
and discovered that some counters do not work as callback is installed too late
when stubs are already generated.

[Jakob Kummerow, 2015-03-18 09:43:51]

+Sven: FYI, API-compatible v8.h change

This patch LGTM.

What's the plan for the old Isolate::SetCounterFunction() and friends? Keep
them, or deprecate them? Do we know of any embedders other than d8 that use
them?

[Vyacheslav Egorov (Google), 2015-03-18 09:45:42]

The CQ bit was checked by vegorov@google.com

[commit-bot: I haz the power, 2015-03-18 09:45:56]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1010233002/1

[commit-bot: I haz the power, 2015-03-18 10:14:55]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2015-03-18 10:15:11]

Patchset 1 (id:??) landed as
https://crrev.com/0e024449b8322f99534c1901ac6acc6611ddcb1d
Cr-Commit-Position: refs/heads/master@{#27262}

[bnoordhuis, 2015-03-18 12:10:03]

On 2015/03/18 09:43:51, Jakob wrote:
> +Sven: FYI, API-compatible v8.h change
> 
> This patch LGTM.
> 
> What's the plan for the old Isolate::SetCounterFunction() and friends? Keep
> them, or deprecate them? Do we know of any embedders other than d8 that use
> them?

We (StrongLoop) use them in our strong-agent product, mostly for quick sanity
checks when customers report issues to us.

I'd be kind of sad to see the counter and histogram functions go because
strong-agent cannot influence the creation of the isolate, it's loaded by io.js
/ node.js at a time when the isolate already exists.  (And yes, I know some
counters don't work or are unreliable at that point but that's not a problem for
what we use them for.)