Implement Visitor::isGlobalMarkingVisitor

Implement Visitor::isGlobalMarkingVisitor

This CL implements Visitor::isGlobalMarkingVisitor, which can be used to query
if the Visitor instance is MarkingVisitor<GlobalMarking> or not.

This method is to be used from TraceTrait<T>::mark to check if it can switch
to inlined global marking visitor implementation.

BUG=420515
Committed: https://src.chromium.org/viewvc/blink?view=rev&revision=187339

[kouhei (in TOK), 2014-12-16 06:45:31]

kouhei@chromium.org changed reviewers:
+ oilpan-reviews@chromium.org

[kouhei (in TOK), 2014-12-16 06:45:32]

This CL is split from https://codereview.chromium.org/803443002/ , to prepare
for InlinedGlobalMarkingVisitor.

[haraken, 2014-12-16 06:53:29]

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

[haraken, 2014-12-16 06:53:30]

LGTM

https://codereview.chromium.org/804303002/diff/1/Source/platform/heap/Visitor.h
File Source/platform/heap/Visitor.h (right):

https://codereview.chromium.org/804303002/diff/1/Source/platform/heap/Visitor...
Source/platform/heap/Visitor.h:542: Visitor(VisitorType type)

Add explicit

https://codereview.chromium.org/804303002/diff/1/Source/platform/heap/Visitor...
Source/platform/heap/Visitor.h:568: bool m_isGlobalMarkingVisitor;

Can we store m_visitorType, instead of m_isGlobalMarkingVisitor?

[kouhei (in TOK), 2014-12-16 06:58:27]

https://codereview.chromium.org/804303002/diff/1/Source/platform/heap/Visitor.h
File Source/platform/heap/Visitor.h (right):

https://codereview.chromium.org/804303002/diff/1/Source/platform/heap/Visitor...
Source/platform/heap/Visitor.h:542: Visitor(VisitorType type)
On 2014/12/16 06:53:30, haraken wrote:
> 
> Add explicit

Done.

https://codereview.chromium.org/804303002/diff/1/Source/platform/heap/Visitor...
Source/platform/heap/Visitor.h:568: bool m_isGlobalMarkingVisitor;
On 2014/12/16 06:53:29, haraken wrote:
> Can we store m_visitorType, instead of m_isGlobalMarkingVisitor?
"type == GlobalMarkingVisitorType" is slower than m_isGlobalMarkingVisitor, so
I'd prefer just a bool here, but it might be a premature optimization.

[kouhei (in TOK), 2014-12-17 04:43:47]

The CQ bit was checked by kouhei@chromium.org

[commit-bot: I haz the power, 2014-12-17 04:44:47]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/804303002/20001

[commit-bot: I haz the power, 2014-12-17 05:04:44]

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

[commit-bot: I haz the power, 2014-12-17 05:04:45]

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

[kouhei (in TOK), 2014-12-17 05:09:45]

The CQ bit was checked by kouhei@chromium.org

[commit-bot: I haz the power, 2014-12-17 05:10:55]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/804303002/40001

[commit-bot: I haz the power, 2014-12-17 05:16:43]

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

[commit-bot: I haz the power, 2014-12-17 05:16:44]

Try jobs failed on following builders:
  mac_blink_compile_dbg on tryserver.blink
(http://build.chromium.org/p/tryserver.blink/builders/mac_blink_compile_dbg/bu...)

[kouhei (in TOK), 2014-12-17 05:35:12]

The CQ bit was checked by kouhei@chromium.org

[commit-bot: I haz the power, 2014-12-17 05:36:09]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/804303002/60001

[commit-bot: I haz the power, 2014-12-17 06:49:50]

Committed patchset #4 (id:60001) as
https://src.chromium.org/viewvc/blink?view=rev&revision=187339