XFA: Pass IFXJS_Runtime via V8 contexts, not V8 isolates

XFA: Pass IFXJS_Runtime via V8 contexts, not V8 isolates

This makes the XFA branch look more like the master.  I suspect a patch
was lost during the intial XFA checkin.

R=jochen@chromium.org

Committed: https://pdfium.googlesource.com/pdfium/+/a25fd09cd880ad82aea09a7ffffe3f8e5b121bbe

[Tom Sepez, 2015-09-25 00:11:50]

tsepez@chromium.org changed reviewers:
+ jochen@chromium.org, thestig@chromium.org

[Tom Sepez, 2015-09-25 00:11:51]

Jochen, for review.

[jochen (gone - plz use gerrit), 2015-09-25 11:17:10]

https://codereview.chromium.org/1366053003/diff/1/fpdfsdk/include/javascript/...
File fpdfsdk/include/javascript/JS_Define.h (right):

https://codereview.chromium.org/1366053003/diff/1/fpdfsdk/include/javascript/...
fpdfsdk/include/javascript/JS_Define.h:452: v8::Local<v8::Value> v =
context->GetEmbedderData(1);
if you use GetAlignedPointerFromInternalField /
SetAlignedPointerFromInternalField, you can store pointers directly in those
slots. However, juggling around with v8::External is also fine.

https://codereview.chromium.org/1366053003/diff/1/fpdfsdk/src/jsapi/fxjs_v8.cpp
File fpdfsdk/src/jsapi/fxjs_v8.cpp (right):

https://codereview.chromium.org/1366053003/diff/1/fpdfsdk/src/jsapi/fxjs_v8.c...
fpdfsdk/src/jsapi/fxjs_v8.cpp:273: v8Context->SetEmbedderData(1, ptr);
we should use kPerContextDataStartIndex + kEmbedderPDFium which is == 3

[Tom Sepez, 2015-09-25 16:40:11]

Jochen, can you sign off on this? That way I can fix the issues on master and
straightforward merge to here?

https://codereview.chromium.org/1366053003/diff/1/fpdfsdk/include/javascript/...
File fpdfsdk/include/javascript/JS_Define.h (right):

https://codereview.chromium.org/1366053003/diff/1/fpdfsdk/include/javascript/...
fpdfsdk/include/javascript/JS_Define.h:452: v8::Local<v8::Value> v =
context->GetEmbedderData(1);
On 2015/09/25 11:17:10, jochen wrote:
> if you use GetAlignedPointerFromInternalField /
> SetAlignedPointerFromInternalField, you can store pointers directly in those
> slots. However, juggling around with v8::External is also fine.
I'll do this in a follow-up patch on master, then merge back here to XFA.

https://codereview.chromium.org/1366053003/diff/1/fpdfsdk/src/jsapi/fxjs_v8.cpp
File fpdfsdk/src/jsapi/fxjs_v8.cpp (right):

https://codereview.chromium.org/1366053003/diff/1/fpdfsdk/src/jsapi/fxjs_v8.c...
fpdfsdk/src/jsapi/fxjs_v8.cpp:273: v8Context->SetEmbedderData(1, ptr);
On 2015/09/25 11:17:10, jochen wrote:
> we should use kPerContextDataStartIndex + kEmbedderPDFium which is == 3

Ok, I'll make a new constant, but I don't want to force the standalone version
to depend on gin/ (though someday reimplementing this in gin might be sane). 
Again, I'd do this on master first, then move over to  XFA.

[jochen (gone - plz use gerrit), 2015-09-28 11:16:52]

lgtm

[Tom Sepez, 2015-09-28 16:06:07]

Committed patchset #1 (id:1) manually as
a25fd09cd880ad82aea09a7ffffe3f8e5b121bbe (presubmit successful).