Fixes ASan crash for an embedded Blink-in-JS component.

Fixes ASan crash for an embedded Blink-in-JS component.

In the test case (in this patch) it appears the Blink-in-JS component tries to run JS during document creation.
However there is a ScriptForbidden scope which throws a "Uncaught Error: Script execution is forbidden." (probably because it is being created in this weird place?)

This patch re-adds the simple check that was removed in https://codereview.chromium.org/1885833002 which checked if the toDOMWindow(isolate->GetEnteredContext()) was null.
(now the check is just isolate->GetEnteredContext()->IsEmpty()).

BUG=617104
Review-Url: https://codereview.chromium.org/2039333002
Cr-Commit-Position: refs/heads/master@{#398310}
(cherry picked from commit 2deeee5b5604eb997fa053a1b6ab4268c662596f)

Committed: https://chromium.googlesource.com/chromium/src/+/0dccfd08b8278a4ac6e3c3ad0698a4e45f3efc0d

[ikilpatrick, 2016-06-08 19:33:50]

Description was changed from

==========
Fixes ASan crash for an embedded Blink-in-JS component.

In the test case (in this patch) it appears the Blink-in-JS component tries to
run JS during document creation.
However there is a ScriptForbidden scope which throws a "Uncaught Error: Script
execution is forbidden." (probably because it is being created in this weird
place?)

This patch re-adds the simple check that was removed in
https://codereview.chromium.org/1885833002 which checked if the
toDOMWindow(isolate->GetEnteredContext()) was null.
(now the check is just isolate->GetEnteredContext()->IsEmpty()).

BUG=617104

Review-Url: https://codereview.chromium.org/2039333002
Cr-Commit-Position: refs/heads/master@{#398310}
(cherry picked from commit 2deeee5b5604eb997fa053a1b6ab4268c662596f)
==========

to

==========
Fixes ASan crash for an embedded Blink-in-JS component.

In the test case (in this patch) it appears the Blink-in-JS component tries to
run JS during document creation.
However there is a ScriptForbidden scope which throws a "Uncaught Error: Script
execution is forbidden." (probably because it is being created in this weird
place?)

This patch re-adds the simple check that was removed in
https://codereview.chromium.org/1885833002 which checked if the
toDOMWindow(isolate->GetEnteredContext()) was null.
(now the check is just isolate->GetEnteredContext()->IsEmpty()).

BUG=617104

Review-Url: https://codereview.chromium.org/2039333002
Cr-Commit-Position: refs/heads/master@{#398310}
(cherry picked from commit 2deeee5b5604eb997fa053a1b6ab4268c662596f)

Committed:
https://chromium.googlesource.com/chromium/src/+/0dccfd08b8278a4ac6e3c3ad0698...
==========

[ikilpatrick, 2016-06-08 19:33:52]

Committed patchset #1 (id:1) manually as
0dccfd08b8278a4ac6e3c3ad0698a4e45f3efc0d.