Introduce kPerIsolateDataIndex and tidy JS_Define.h

Introduce kPerIsolateDataIndex and tidy JS_Define.h

Follow-up from https://codereview.chromium.org/1366053003/

- use kPerIsolateDataIndex rather than magic constant 1.
- make a helper function for common code in JS_Define.h
- remove dead prototypes missed in earlier CL.
- fxjs_v8 can't include generic fpdfsdk includes (layering).

R=jochen@chromium.org

Committed: https://pdfium.googlesource.com/pdfium/+/cfff2f65aaec70247d020188bc68a0dc4fb34c3e

[Tom Sepez, 2015-09-25 17:22:31]

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

[Tom Sepez, 2015-09-25 17:32:18]

Jochen, for review, but also a question.

https://codereview.chromium.org/1367813003/diff/1/fpdfsdk/src/jsapi/fxjs_v8.cpp
File fpdfsdk/src/jsapi/fxjs_v8.cpp (right):

https://codereview.chromium.org/1367813003/diff/1/fpdfsdk/src/jsapi/fxjs_v8.c...
fpdfsdk/src/jsapi/fxjs_v8.cpp:283: v8::Local<v8::External> ptr =
v8::External::New(pIsolate, pFXRuntime);
Here's the spot where I'd like to use the AlignedPointer methods, but I'm not
sure how to go about this.  Do I need an ordinary v8::Object here that would
hold it in a slot?  Would this object still be set in the context's
kPerContextDataIndex slot?

A code fragment might be illuminating.

[jochen (gone - plz use gerrit), 2015-09-28 11:27:31]

https://codereview.chromium.org/1367813003/diff/1/fpdfsdk/src/jsapi/fxjs_v8.cpp
File fpdfsdk/src/jsapi/fxjs_v8.cpp (right):

https://codereview.chromium.org/1367813003/diff/1/fpdfsdk/src/jsapi/fxjs_v8.c...
fpdfsdk/src/jsapi/fxjs_v8.cpp:283: v8::Local<v8::External> ptr =
v8::External::New(pIsolate, pFXRuntime);
On 2015/09/25 at 17:32:18, Tom Sepez wrote:
> Here's the spot where I'd like to use the AlignedPointer methods, but I'm not
sure how to go about this.  Do I need an ordinary v8::Object here that would
hold it in a slot?  Would this object still be set in the context's
kPerContextDataIndex slot?
> 
> A code fragment might be illuminating.

v8Context->SetAlignedPointerInEmbedderData(kPerContextDataIndex, pFXRuntime);
should do the trick

[Tom Sepez, 2015-09-28 16:20:18]

OK, please take another look.

https://codereview.chromium.org/1367813003/diff/1/fpdfsdk/src/jsapi/fxjs_v8.cpp
File fpdfsdk/src/jsapi/fxjs_v8.cpp (right):

https://codereview.chromium.org/1367813003/diff/1/fpdfsdk/src/jsapi/fxjs_v8.c...
fpdfsdk/src/jsapi/fxjs_v8.cpp:283: v8::Local<v8::External> ptr =
v8::External::New(pIsolate, pFXRuntime);
On 2015/09/28 11:27:31, jochen wrote:
> On 2015/09/25 at 17:32:18, Tom Sepez wrote:
> > Here's the spot where I'd like to use the AlignedPointer methods, but I'm
not
> sure how to go about this.  Do I need an ordinary v8::Object here that would
> hold it in a slot?  Would this object still be set in the context's
> kPerContextDataIndex slot?
> > 
> > A code fragment might be illuminating.
> 
> v8Context->SetAlignedPointerInEmbedderData(kPerContextDataIndex, pFXRuntime);
> should do the trick

Done. Appears to work (I thought I'd tried this earlier but got segvs, which is
why I asked).

[jochen (gone - plz use gerrit), 2015-09-28 16:30:59]

lgtm

[Tom Sepez, 2015-09-28 16:44:59]

Committed patchset #2 (id:20001) manually as
cfff2f65aaec70247d020188bc68a0dc4fb34c3e (presubmit successful).