Switch blink to use a gin-managed isolate.

Switch blink to use a gin-managed isolate.

This also moves the basic V8 initialization to gin. The main advantage
is that we now initialize V8 first and then start creating isolates. It
also removes some code duplication.

BUG=none
R=haraken@chromium.org,andrewhayden@chromium.org

Committed: https://src.chromium.org/viewvc/blink?view=rev&revision=181832

[haraken, 2014-09-11 09:07:06]

LGTM, assuming that a couple of V8 setups you removed from this CL (e.g.,
v8::SetResourceConstraints, v8::V8::SetEntropySource,
v8::V8::SetArrayBufferAllocator) are already conducted in the gin side.

https://codereview.chromium.org/559363002/diff/1/Source/bindings/core/v8/V8Pe...
File Source/bindings/core/v8/V8PerIsolateData.cpp (left):

https://codereview.chromium.org/559363002/diff/1/Source/bindings/core/v8/V8Pe...
Source/bindings/core/v8/V8PerIsolateData.cpp:129:
isolate->SetData(gin::kEmbedderBlink, 0);

Why did you remove this? I guess it would be better to clear the data just in
case.

https://codereview.chromium.org/559363002/diff/1/Source/bindings/core/v8/V8Pe...
File Source/bindings/core/v8/V8PerIsolateData.cpp (right):

https://codereview.chromium.org/559363002/diff/1/Source/bindings/core/v8/V8Pe...
Source/bindings/core/v8/V8PerIsolateData.cpp:66: , m_stringCache(adoptPtr(new
StringCache(m_isolateHolder->isolate())))

m_isolateHolder->isolate() => isolate() ?

https://codereview.chromium.org/559363002/diff/1/Source/bindings/core/v8/V8Pe...
Source/bindings/core/v8/V8PerIsolateData.cpp:129: isolate->Exit();

Just help me understand: What's the relationship between Isolate::GetCurrent and
Isolate::Enter/Exit?

[jochen (gone - plz use gerrit), 2014-09-11 11:43:48]

On 2014/09/11 at 09:07:06, haraken wrote:
> LGTM, assuming that a couple of V8 setups you removed from this CL (e.g.,
v8::SetResourceConstraints, v8::V8::SetEntropySource,
v8::V8::SetArrayBufferAllocator) are already conducted in the gin side.


Yes. And since both the gin and the blink versions are based on the same //base
methods, it's only moving the calls around.

> 
>
https://codereview.chromium.org/559363002/diff/1/Source/bindings/core/v8/V8Pe...
> File Source/bindings/core/v8/V8PerIsolateData.cpp (left):
> 
>
https://codereview.chromium.org/559363002/diff/1/Source/bindings/core/v8/V8Pe...
> Source/bindings/core/v8/V8PerIsolateData.cpp:129:
isolate->SetData(gin::kEmbedderBlink, 0);
> 
> Why did you remove this? I guess it would be better to clear the data just in
case.

The isolate is now destroyed as part of the V8PerIsolateData dtor, however, the
string cache's dtor (via StringCacheMapTraits::Dispose) uses
V8PerIsolateData::from().

Then again, the V8PerIsolateData will discard the isolate as its last action, so
there's nothing happening inbetween.

> 
>
https://codereview.chromium.org/559363002/diff/1/Source/bindings/core/v8/V8Pe...
> File Source/bindings/core/v8/V8PerIsolateData.cpp (right):
> 
>
https://codereview.chromium.org/559363002/diff/1/Source/bindings/core/v8/V8Pe...
> Source/bindings/core/v8/V8PerIsolateData.cpp:66: , m_stringCache(adoptPtr(new
StringCache(m_isolateHolder->isolate())))
> 
> m_isolateHolder->isolate() => isolate() ?

done

> 
>
https://codereview.chromium.org/559363002/diff/1/Source/bindings/core/v8/V8Pe...
> Source/bindings/core/v8/V8PerIsolateData.cpp:129: isolate->Exit();
> 
> Just help me understand: What's the relationship between Isolate::GetCurrent
and Isolate::Enter/Exit?

GetCurrent() returns the isolate found in TLS. Enter/Exit installs the isolate
in TLS

[haraken, 2014-09-11 11:51:43]

> > Just help me understand: What's the relationship between Isolate::GetCurrent
> and Isolate::Enter/Exit?
> 
> GetCurrent() returns the isolate found in TLS. Enter/Exit installs the isolate
> in TLS

Makes sense. Still LGTM.

[jochen (gone - plz use gerrit), 2014-09-11 11:54:23]

The CQ bit was checked by jochen@chromium.org

[commit-bot: I haz the power, 2014-09-11 11:55:00]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patchset/559363002/20001

[commit-bot: I haz the power, 2014-09-11 13:17:01]

The CQ bit was unchecked by commit-bot@chromium.org

[commit-bot: I haz the power, 2014-09-11 13:17:02]

Try jobs failed on following builders:
  linux_blink_rel on tryserver.blink
(http://build.chromium.org/p/tryserver.blink/builders/linux_blink_rel/builds/2...)

[jochen (gone - plz use gerrit), 2014-09-11 16:07:07]

The CQ bit was checked by jochen@chromium.org

[commit-bot: I haz the power, 2014-09-11 16:08:13]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patchset/559363002/20001

[commit-bot: I haz the power, 2014-09-11 17:14:35]

Committed patchset #2 (id:20001) as 181832