Move gc notifications from V8 to Isolate and make idle hint mandatory

Move gc notifications from V8 to Isolate and make idle hint mandatory

Embedders should use e.g. isolate->IdleNotification(1000) instead
of v8::V8::IdleNotification()

BUG=397026
R=hpayer@chromium.org, ernstm@chromium.org
LOG=y

Committed: https://code.google.com/p/v8/source/detail?r=22584

[Hannes Payer (out of office), 2014-07-24 08:25:56]

lgtm, just nits

https://codereview.chromium.org/412163003/diff/1/include/v8.h
File include/v8.h (right):

https://codereview.chromium.org/412163003/diff/1/include/v8.h#newcode4470
include/v8.h:4470: * The idle_time_hint_ms argument specifies the time  V8 has
to do reduce
remove one blank in between time    V8

https://codereview.chromium.org/412163003/diff/1/include/v8.h#newcode4470
include/v8.h:4470: * The idle_time_hint_ms argument specifies the time  V8 has
to do reduce
I would prefer idle_time_in_ms

https://codereview.chromium.org/412163003/diff/1/include/v8.h#newcode4474
include/v8.h:4474: bool IdleNotification(int idle_time_hint_ms);
idle_time_in_ms

https://codereview.chromium.org/412163003/diff/1/src/api.cc
File src/api.cc (right):

https://codereview.chromium.org/412163003/diff/1/src/api.cc#newcode6715
src/api.cc:6715: bool v8::Isolate::IdleNotification(int idle_time_hint_ms) {
idle_time_in_ms

[jochen (gone - plz use gerrit), 2014-07-24 08:28:11]

Committed patchset #2 manually as r22584 (presubmit successful).