[debugger] correctly find function context.

[debugger] correctly find function context.

In the debugger we are interested in getting the context for the
current frame, which is usually a function context. To do that,
we used to call Context::declaration_context, which may also
return a block context. This is wrong and can lead to crashes.
Instead, we now use a newly introduced Context::closure_context,
which skips block contexts. This works fine for the debugger,
since we have other means to find and materialize block contexts.

R=rossberg@chromium.org
BUG=chromium:582051
LOG=N

Committed: https://crrev.com/835b038331b0fd4d351d9cb5ffbccef186b9919f
Cr-Commit-Position: refs/heads/master@{#33627}

[Yang, 2016-01-29 14:44:11]

The CQ bit was checked by yangguo@chromium.org to run a CQ dry run

[commit-bot: I haz the power, 2016-01-29 14:44:23]

Dry run: CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1648263002/1
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1648263002/1

[commit-bot: I haz the power, 2016-01-29 15:05:45]

The CQ bit was unchecked by commit-bot@chromium.org

[commit-bot: I haz the power, 2016-01-29 15:05:46]

Dry run: Try jobs failed on following builders:
  v8_linux_dbg_ng on tryserver.v8 (JOB_FAILED,
http://build.chromium.org/p/tryserver.v8/builders/v8_linux_dbg_ng/builds/690)
  v8_linux_dbg_ng_triggered on tryserver.v8 (JOB_FAILED,
http://build.chromium.org/p/tryserver.v8/builders/v8_linux_dbg_ng_triggered/b...)

[Yang, 2016-01-29 15:08:07]

The CQ bit was checked by yangguo@chromium.org to run a CQ dry run

[commit-bot: I haz the power, 2016-01-29 15:08:20]

Dry run: CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1648263002/20001
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1648263002/20001

[commit-bot: I haz the power, 2016-01-29 15:35:50]

The CQ bit was unchecked by commit-bot@chromium.org

[commit-bot: I haz the power, 2016-01-29 15:35:51]

Dry run: This issue passed the CQ dry run.

[rossberg, 2016-01-29 19:46:25]

LGTM modulo nit

https://codereview.chromium.org/1648263002/diff/20001/src/contexts.h
File src/contexts.h (right):

https://codereview.chromium.org/1648263002/diff/20001/src/contexts.h#newcode454
src/contexts.h:454: Context* local_context();
Nit: Scope has an analogous method called ClosureScope, so I'd prefer
"closure_context", which is a somewhat more telling name as well.

[Yang, 2016-02-01 06:28:45]

https://codereview.chromium.org/1648263002/diff/20001/src/contexts.h
File src/contexts.h (right):

https://codereview.chromium.org/1648263002/diff/20001/src/contexts.h#newcode454
src/contexts.h:454: Context* local_context();
On 2016/01/29 19:46:25, rossberg wrote:
> Nit: Scope has an analogous method called ClosureScope, so I'd prefer
> "closure_context", which is a somewhat more telling name as well.

Done.

[Yang, 2016-02-01 06:28:49]

The CQ bit was checked by yangguo@chromium.org

[Yang, 2016-02-01 06:28:49]

The patchset sent to the CQ was uploaded after l-g-t-m from
rossberg@chromium.org
Link to the patchset: https://codereview.chromium.org/1648263002/#ps40001
(title: "addressed comments")

[commit-bot: I haz the power, 2016-02-01 06:28:59]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1648263002/40001
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1648263002/40001

[Yang, 2016-02-01 06:29:07]

Description was changed from

==========
[debugger] correctly find function context.

In the debugger we are interested in getting the context for the
current frame, which is usually a function context. To do that,
we used to call Context::declaration_context, which may also
return a block context. This is wrong and can lead to crashes.
Instead, we now use a newly introduced Context::local_context,
which skips block contexts. This works fine for the debugger,
since we have other means to find and materialize block contexts.

R=rossberg@chromium.org
BUG=chromium:582051
LOG=N
==========

to

==========
[debugger] correctly find function context.

In the debugger we are interested in getting the context for the
current frame, which is usually a function context. To do that,
we used to call Context::declaration_context, which may also
return a block context. This is wrong and can lead to crashes.
Instead, we now use a newly introduced Context::closure_context,
which skips block contexts. This works fine for the debugger,
since we have other means to find and materialize block contexts.

R=rossberg@chromium.org
BUG=chromium:582051
LOG=N
==========

[commit-bot: I haz the power, 2016-02-01 07:03:16]

Description was changed from

==========
[debugger] correctly find function context.

In the debugger we are interested in getting the context for the
current frame, which is usually a function context. To do that,
we used to call Context::declaration_context, which may also
return a block context. This is wrong and can lead to crashes.
Instead, we now use a newly introduced Context::closure_context,
which skips block contexts. This works fine for the debugger,
since we have other means to find and materialize block contexts.

R=rossberg@chromium.org
BUG=chromium:582051
LOG=N
==========

to

==========
[debugger] correctly find function context.

In the debugger we are interested in getting the context for the
current frame, which is usually a function context. To do that,
we used to call Context::declaration_context, which may also
return a block context. This is wrong and can lead to crashes.
Instead, we now use a newly introduced Context::closure_context,
which skips block contexts. This works fine for the debugger,
since we have other means to find and materialize block contexts.

R=rossberg@chromium.org
BUG=chromium:582051
LOG=N
==========

[commit-bot: I haz the power, 2016-02-01 07:03:18]

Committed patchset #3 (id:40001)

[commit-bot: I haz the power, 2016-02-01 07:03:49]

Description was changed from

==========
[debugger] correctly find function context.

In the debugger we are interested in getting the context for the
current frame, which is usually a function context. To do that,
we used to call Context::declaration_context, which may also
return a block context. This is wrong and can lead to crashes.
Instead, we now use a newly introduced Context::closure_context,
which skips block contexts. This works fine for the debugger,
since we have other means to find and materialize block contexts.

R=rossberg@chromium.org
BUG=chromium:582051
LOG=N
==========

to

==========
[debugger] correctly find function context.

In the debugger we are interested in getting the context for the
current frame, which is usually a function context. To do that,
we used to call Context::declaration_context, which may also
return a block context. This is wrong and can lead to crashes.
Instead, we now use a newly introduced Context::closure_context,
which skips block contexts. This works fine for the debugger,
since we have other means to find and materialize block contexts.

R=rossberg@chromium.org
BUG=chromium:582051
LOG=N

Committed: https://crrev.com/835b038331b0fd4d351d9cb5ffbccef186b9919f
Cr-Commit-Position: refs/heads/master@{#33627}
==========

[commit-bot: I haz the power, 2016-02-01 07:03:50]

Patchset 3 (id:??) landed as
https://crrev.com/835b038331b0fd4d351d9cb5ffbccef186b9919f
Cr-Commit-Position: refs/heads/master@{#33627}