Reason for revert:
[Sheriff] Layout test changes.
Original issue's description:
> [debugger] debug-evaluate should not not modify local values.
>
> Debug evaluate no longer writes back changes to the replicated
> context chain to the original after execution. Changes to the
> global object or script contexts still stick. Calling functions
> that bind to the original context chain also have their expected
> side effects.
>
> As far as I can tell, DevTools is not interested in modifying
> local variable values. Modifying global variable values still
> works as expected. However, I have not yet removed the old
> implementation, but merely keep it behind a flag.
>
> R=mstarzinger@chromium.org, rossberg@chromium.org
>
> Committed: https://crrev.com/92caa9b85eefffbef51c67428397951bd2e2c330
> Cr-Commit-Position: refs/heads/master@{#32841}
TBR=mstarzinger@chromium.org,rossberg@chromium.org,yangguo@chromium.org
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
Review URL: https://codereview.chromium.org/1526553003
Cr-Commit-Position: refs/heads/master@{#32845}
Debug evaluate no longer writes back changes to the replicated
context chain to the original after execution. Changes to the
global object or script contexts still stick. Calling functions
that bind to the original context chain also have their expected
side effects.
As far as I can tell, DevTools is not interested in modifying
local variable values. Modifying global variable values still
works as expected. However, I have not yet removed the old
implementation, but merely keep it behind a flag.
R=mstarzinger@chromium.org, rossberg@chromium.org
Review URL: https://codereview.chromium.org/1513183003
Cr-Commit-Position: refs/heads/master@{#32841}
Debug-evaluate used to resolve stack variables that shadow
context variables incorrectly, since the stack variable is
not visible in the context chain.
To fix this, we limit local variables accessible by debug-
evaluate to the ones directly referenced inside the function.
What is not referenced by the function itself, is considered
optimized out and not accessible by debug-evaluate.
To achieve this, we duplicate the entire context chain up to
the native context, and write back changes after debug-
evaluate. Changes to the original context chain will however
be overwritten. This already happens for catch and block
scopes though.
Also fix a crash caused by declaring variables inside debug-
evaluate.
R=mstarzinger@chromium.org
BUG=v8:4593
LOG=N
Review URL: https://codereview.chromium.org/1500933002
Cr-Commit-Position: refs/heads/master@{#32828}
