Fix performance issue in InstanceCounters for DOM nodes

Fix performance issue in InstanceCounters for DOM nodes

The instance counters have used atomic incrementing/decrementing, but
this caused performance issue for dromaeo.domcoremodify test where DOM
objects are injected and created. This CL fixes this issue by creating
another counter without locks or atomic barriers only for nodes.

BUG=641019
Committed: https://crrev.com/964d6ecc9c556e80c53140a2254e93c92deb98a2
Cr-Commit-Position: refs/heads/master@{#423501}

[hajimehoshi, 2016-10-06 08:43:23]

The CQ bit was checked by hajimehoshi@chromium.org to run a CQ dry run

[commit-bot: I haz the power, 2016-10-06 08:43:35]

Dry run: CQ is trying da patch. Follow status at
 
https://chromium-cq-status.appspot.com/v2/patch-status/codereview.chromium.or...

[hajimehoshi, 2016-10-06 08:44:02]

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

[hajimehoshi, 2016-10-06 08:44:03]

PTAL

[haraken, 2016-10-06 08:47:10]

LGTM

https://codereview.chromium.org/2393353003/diff/1/third_party/WebKit/Source/c...
File third_party/WebKit/Source/core/inspector/InstanceCounters.cpp (right):

https://codereview.chromium.org/2393353003/diff/1/third_party/WebKit/Source/c...
third_party/WebKit/Source/core/inspector/InstanceCounters.cpp:37: int
InstanceCounters::s_nodeCounter;

Add a comment and mention why we want to have a different counter for Nodes.

[hajimehoshi, 2016-10-06 09:34:52]

Thank you!

https://codereview.chromium.org/2393353003/diff/1/third_party/WebKit/Source/c...
File third_party/WebKit/Source/core/inspector/InstanceCounters.cpp (right):

https://codereview.chromium.org/2393353003/diff/1/third_party/WebKit/Source/c...
third_party/WebKit/Source/core/inspector/InstanceCounters.cpp:37: int
InstanceCounters::s_nodeCounter;
On 2016/10/06 08:47:10, haraken wrote:
> 
> Add a comment and mention why we want to have a different counter for Nodes.

Done.

[hajimehoshi, 2016-10-06 09:34:58]

The CQ bit was checked by hajimehoshi@chromium.org

[hajimehoshi, 2016-10-06 09:34:58]

The patchset sent to the CQ was uploaded after l-g-t-m from haraken@chromium.org
Link to the patchset: https://codereview.chromium.org/2393353003/#ps20001
(title: "Address on reviews")

[commit-bot: I haz the power, 2016-10-06 09:35:14]

CQ is trying da patch. Follow status at
 
https://chromium-cq-status.appspot.com/v2/patch-status/codereview.chromium.or...

[commit-bot: I haz the power, 2016-10-06 11:43:35]

Committed patchset #2 (id:20001)

[commit-bot: I haz the power, 2016-10-06 11:46:59]

Description was changed from

==========
Fix performance issue in InstanceCounters for DOM nodes

The instance counters have used atomic incrementing/decrementing, but
this caused performance issue for dromaeo.domcoremodify test where DOM
objects are injected and created. This CL fixes this issue by creating
another counter without locks or atomic barriers only for nodes.

BUG=641019
==========

to

==========
Fix performance issue in InstanceCounters for DOM nodes

The instance counters have used atomic incrementing/decrementing, but
this caused performance issue for dromaeo.domcoremodify test where DOM
objects are injected and created. This CL fixes this issue by creating
another counter without locks or atomic barriers only for nodes.

BUG=641019

Committed: https://crrev.com/964d6ecc9c556e80c53140a2254e93c92deb98a2
Cr-Commit-Position: refs/heads/master@{#423501}
==========

[commit-bot: I haz the power, 2016-10-06 11:46:59]

Patchset 2 (id:??) landed as
https://crrev.com/964d6ecc9c556e80c53140a2254e93c92deb98a2
Cr-Commit-Position: refs/heads/master@{#423501}