[V8] Added DebugEvaluateContext to DCHECKs in contexts.cc

[V8] Added DebugEvaluateContext to DCHECKs in contexts.cc

DebugEvaluate context was introduced in [1]. With this CL DevTools has started to crash in console-save-to-temp-var.html test on debug bots.
IsDebugEvaluateContext alternative is added to three DCHECKs in contexts.cc to avoid this crash.

[1] https://chromium.googlesource.com/v8/v8/+/297daf6c37d6e4145e8aaec12ccc9762ac180850

BUG=chromium:599662
R=yangguo@chromium.org

[kozy, 2016-04-04 23:57:10]

Yang, please take a look.
Probably some additions changed are required.

[Yang, 2016-04-05 08:28:01]

I don't think this is the correct fix.

I came up with another: https://codereview.chromium.org/1859033002

Unfortunately I currently have no way to run layout tests. Could you verify
whether this fixes the crash?

https://codereview.chromium.org/1856203002/diff/1/src/contexts.cc
File src/contexts.cc (right):

https://codereview.chromium.org/1856203002/diff/1/src/contexts.cc#newcode94
src/contexts.cc:94: IsDebugEvaluateContext());
I don't think this can happen. We don't even expect a with-context at this
point.

https://codereview.chromium.org/1856203002/diff/1/src/contexts.cc#newcode109
src/contexts.cc:109: IsBlockContext() || IsDebugEvaluateContext());
This should not happen. The only place I can see this being called with a
debug-evaluate context is from the ScopeIterator. It should however not expose
debug-evaluate contexts. Otherwise it might be confusing for the user.

[kozy, 2016-04-06 04:52:57]

Description was changed from

==========
[V8] Added DebugEvaluateContext to DCHECKs in contexts.cc

DebugEvaluate context was introduced in [1]. With this CL DevTools has started
to crash in console-save-to-temp-var.html test on debug bots.
IsDebugEvaluateContext alternative is added to three DCHECKs in contexts.cc to
avoid this crash.

[1]
https://chromium.googlesource.com/v8/v8/+/297daf6c37d6e4145e8aaec12ccc9762ac1...

BUG=chromium:599662
R=yangguo@chromium.org
==========

to

==========
[V8] Added DebugEvaluateContext to DCHECKs in contexts.cc

DebugEvaluate context was introduced in [1]. With this CL DevTools has started
to crash in console-save-to-temp-var.html test on debug bots.
IsDebugEvaluateContext alternative is added to three DCHECKs in contexts.cc to
avoid this crash.

[1]
https://chromium.googlesource.com/v8/v8/+/297daf6c37d6e4145e8aaec12ccc9762ac1...

BUG=chromium:599662
R=yangguo@chromium.org
==========

[kozy, 2016-04-06 04:53:40]

On 2016/04/05 08:28:01, Yang wrote:
> I don't think this is the correct fix.
> 
> I came up with another: https://codereview.chromium.org/1859033002
> 
> Unfortunately I currently have no way to run layout tests. Could you verify
> whether this fixes the crash?
> 
> https://codereview.chromium.org/1856203002/diff/1/src/contexts.cc
> File src/contexts.cc (right):
> 
> https://codereview.chromium.org/1856203002/diff/1/src/contexts.cc#newcode94
> src/contexts.cc:94: IsDebugEvaluateContext());
> I don't think this can happen. We don't even expect a with-context at this
> point.
> 
> https://codereview.chromium.org/1856203002/diff/1/src/contexts.cc#newcode109
> src/contexts.cc:109: IsBlockContext() || IsDebugEvaluateContext());
> This should not happen. The only place I can see this being called with a
> debug-evaluate context is from the ScopeIterator. It should however not expose
> debug-evaluate contexts. Otherwise it might be confusing for the user.

I've checked test with your CL, it works. Thank you!