bindings: Fixes perf regression by crrev.com/646523004.

bindings: Fixes perf regression by crrev.com/646523004.

Window has custom toV8 function, and Window inherits from EventTarget.
So, EventTarget also has custom toV8 because an EventTarget can be a
Window.

crrev.com/646523004 made Node to call EventTarget-version of
v8SetReturnValueForMainWorld because Node inherits from EventTarget,
and it calls toV8 function every time. It caused a perf regression.

This CL adds a new version of v8SetReturnValueForMainWorld for Node
and its subclasses so that they can use the fastest path.

class hierarchy:
    ScriptWrappable <-- EventTarget <--+-- Node <-- ...
                                       +-- Window
overloads:
    v8SetReturnValueForMainWorld(ScriptWrappable*)
        Optimized and very fast.
    v8SetReturnValueForMainWorld(EventTarget*)
        Uses custom toV8 function and slow.
    v8SetReturnValueForMainWorld(Node*)  <----------- NEW!!
        Optimized and very fast.
    v8SetReturnValueForMainWorld(Window*)
        Uses custom toV8 function and slow.

Before this CL:
Element matches EventTarget version of
v8SetReturnValueForMainWorld, and it's very slow.

After this CL:
Element matches Node version of
v8SetReturnValueForMainWorld, and it's very fast.

BUG=428707, 235436
Committed: https://src.chromium.org/viewvc/blink?view=rev&revision=184860

[Yuki, 2014-10-31 15:25:33]

yukishiino@chromium.org changed reviewers:
+ haraken@chromium.org

[Yuki, 2014-10-31 15:25:34]

Could you review this CL?

[haraken, 2014-11-01 22:45:50]

LGTM

https://codereview.chromium.org/684763004/diff/1/Source/bindings/templates/in...
File Source/bindings/templates/interface.h (right):

https://codereview.chromium.org/684763004/diff/1/Source/bindings/templates/in...
Source/bindings/templates/interface.h:191: v8::Handle<v8::Value>
toV8({{cpp_class}}*, v8::Handle<v8::Object> creationContext, v8::Isolate*);

Can we rename this to toV8Custom (for consistency with wrapCustom)? A follow-up
CL is fine.

[Yuki, 2014-11-04 05:48:17]

https://codereview.chromium.org/684763004/diff/1/Source/bindings/templates/in...
File Source/bindings/templates/interface.h (right):

https://codereview.chromium.org/684763004/diff/1/Source/bindings/templates/in...
Source/bindings/templates/interface.h:191: v8::Handle<v8::Value>
toV8({{cpp_class}}*, v8::Handle<v8::Object> creationContext, v8::Isolate*);
On 2014/11/01 22:45:50, haraken wrote:
> 
> Can we rename this to toV8Custom (for consistency with wrapCustom)? A
follow-up
> CL is fine.

Unlike wrap/wrapCustom, toV8 is used as a public API, so it would be better to
keep the same name.  Or we can add a new toV8Custom as the following.

toV8(...) {
  return toV8Custom(...);
}

toV8Custom(...) {
  // implementation
}

[Yuki, 2014-11-04 05:48:23]

The CQ bit was checked by yukishiino@chromium.org

[commit-bot: I haz the power, 2014-11-04 05:49:01]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/684763004/20001

[commit-bot: I haz the power, 2014-11-04 05:59:36]

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

[commit-bot: I haz the power, 2014-11-04 05:59:37]

Try jobs failed on following builders:
  linux_blink_rel on tryserver.blink
(http://build.chromium.org/p/tryserver.blink/builders/linux_blink_rel/builds/3...)

[Yuki, 2014-11-04 14:12:36]

The CQ bit was checked by yukishiino@chromium.org

[commit-bot: I haz the power, 2014-11-04 14:12:51]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/684763004/40001

[commit-bot: I haz the power, 2014-11-04 15:09:52]

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

[commit-bot: I haz the power, 2014-11-04 15:09:54]

Try jobs failed on following builders:
  linux_blink_rel on tryserver.blink
(http://build.chromium.org/p/tryserver.blink/builders/linux_blink_rel/builds/3...)

[haraken, 2014-11-05 09:02:36]

LGTM

[Yuki, 2014-11-05 09:05:08]

The CQ bit was checked by yukishiino@chromium.org

[commit-bot: I haz the power, 2014-11-05 09:05:35]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/684763004/80001

[commit-bot: I haz the power, 2014-11-05 09:50:42]

Committed patchset #5 (id:80001) as 184860