Add safe numerics classes, imported from Chromium

Add safe numerics classes, imported from Chromium.

Not used for anything yet.

R=jochen@chromium.org

Committed: https://code.google.com/p/v8/source/detail?r=21883

[Jakob Kummerow, 2014-06-16 13:08:23]

Jochen: PTAL.

Michael: FYI.

[mvstanton, 2014-06-16 13:09:39]

Thanks, it will be helpful to me!

[Jakob Kummerow, 2014-06-16 13:12:33]

On 2014/06/16 13:08:23, Jakob wrote:
> Jochen: PTAL.

To clarify: patch set 1 is those four files exactly as they are in the Chromium
repo. So you'll probably want to review just the diff to patch set 2, which
contains all the modifications I had to make.

[jochen (gone - plz use gerrit), 2014-06-16 14:25:46]

lgtm with nits

https://codereview.chromium.org/336183003/diff/60001/src/base/safe_conversion...
File src/base/safe_conversions_impl.h (right):

https://codereview.chromium.org/336183003/diff/60001/src/base/safe_conversion...
src/base/safe_conversions_impl.h:8: #ifndef BASE_SAFE_CONVERSIONS_IMPL_H_
please use V8_BASE_SAFE_CONVERSIONS_IMPL_H_

https://codereview.chromium.org/336183003/diff/60001/src/base/safe_conversion...
src/base/safe_conversions_impl.h:16: namespace internal {
please use namespace v8::base in the base library

[Jakob Kummerow, 2014-06-17 13:53:20]

https://codereview.chromium.org/336183003/diff/60001/src/base/safe_conversion...
File src/base/safe_conversions_impl.h (right):

https://codereview.chromium.org/336183003/diff/60001/src/base/safe_conversion...
src/base/safe_conversions_impl.h:8: #ifndef BASE_SAFE_CONVERSIONS_IMPL_H_
On 2014/06/16 14:25:46, jochen traveling until Jun 23 wrote:
> please use V8_BASE_SAFE_CONVERSIONS_IMPL_H_

Done.

https://codereview.chromium.org/336183003/diff/60001/src/base/safe_conversion...
src/base/safe_conversions_impl.h:16: namespace internal {
On 2014/06/16 14:25:46, jochen traveling until Jun 23 wrote:
> please use namespace v8::base in the base library

Done.

[Jakob Kummerow, 2014-06-18 11:02:06]

Committed patchset #3 manually as r21883 (tree was closed).