[M108 Aura Migration][NaCl][PPFW] Fix crash when get render process in UnregisterPepperExtensionDelegate.
EWeb View will destruct in EvasObjectDelete callback called.
If ewk_shutdown called before EvasObjectDelete, it may cause crash
during get render process in UnregisterPepperExtensionDelegate,
which is in EWeb View destructor.
This change is for
DF190114-00719
from M94 Aura Patch:
https://review.tizen.org/gerrit/#/c/platform/framework/web/chromium-efl/+/279978/
Change-Id: I76685eb3ea0a9e2c1fcfc9aeedf476b52813ac05
Signed-off-by: pengxia <pengxia.shen@samsung.com>