Daniel Cheng (Gerrit)

unread,

Mar 24, 2026, 1:50:33 PM (9 days ago) Mar 24

to gate kibr, Daniel Cheng, AyeAye, Lei Zhang, tracing...@chromium.org, wfh+...@chromium.org, spang...@chromium.org, asvitki...@chromium.org, chromiumme...@microsoft.com

Attention needed from Lei Zhang and gate kibr

Daniel Cheng voted Code-Review+1

Code-Review

+1

Open in Gerrit

Related details

Attention is currently required from:

Lei Zhang
gate kibr

Submit Requirements:

Code-Coverage
Code-Owners
Code-Review
Review-Enforcement

Inspect html for hidden footers to help with email filtering. To unsubscribe visit settings.

Gerrit

satisfied_requirement

unsatisfied_requirement

open

diffy

gate kibr (Gerrit)

unread,

Mar 26, 2026, 9:32:06 PM (7 days ago) Mar 26

to Daniel Cheng, AyeAye, Lei Zhang, tracing...@chromium.org, wfh+...@chromium.org, spang...@chromium.org, asvitki...@chromium.org, chromiumme...@microsoft.com

Attention needed from Lei Zhang

gate kibr added 1 comment

Patchset-level comments

File-level comment, Patchset 13 (Latest):

gate kibr . resolved

Can submit it CQ for me

Open in Gerrit

Related details

Attention is currently required from:

Lei Zhang

Submit Requirements:

Code-Coverage
Code-Owners
Code-Review
Review-Enforcement

Inspect html for hidden footers to help with email filtering. To unsubscribe visit settings.

Gerrit

satisfied_requirement

unsatisfied_requirement

open

diffy

Lei Zhang (Gerrit)

unread,

Mar 26, 2026, 10:08:22 PM (7 days ago) Mar 26

to gate kibr, Daniel Cheng, AyeAye, Lei Zhang, tracing...@chromium.org, wfh+...@chromium.org, spang...@chromium.org, asvitki...@chromium.org, chromiumme...@microsoft.com

Attention needed from gate kibr

Lei Zhang added 3 comments

File base/metrics/field_trial_params.cc

Line 145, Patchset 13 (Latest): auto [it, inserted] = trial_groups.emplace(trial, group);

Lei Zhang . unresolved

I personally prefer:

```
bool inserted = some_container_call().second;
if (!inserted) {
   ...
}
```

Then there is no unused `it` variable.

Line 156, Patchset 13 (Latest): params[std::move(key)] = std::move(value);

Lei Zhang . unresolved

Just combine with previous line.

File base/scoped_add_feature_flags.cc

Line 88, Patchset 13 (Latest):

  if (enable) {
    enabled_features_.emplace_back(std::move(feature_name));
  } else {
    disabled_features_.emplace_back(std::move(feature_name));
  }

Lei Zhang . unresolved

Can simplify further:

```
auto& container = enable ? enabled_features_ : disabled_features_;
container.emplace_back(...);
```

Open in Gerrit

Related details

Attention is currently required from:

gate kibr

Submit Requirements:

Code-Coverage
Code-Owners
Code-Review

No-Unresolved-Comments

Review-Enforcement

Inspect html for hidden footers to help with email filtering. To unsubscribe visit settings.

Gerrit

satisfied_requirement

unsatisfied_requirement

open

diffy

Will Harris (Gerrit)

unread,

Mar 26, 2026, 10:14:25 PM (7 days ago) Mar 26

to gate kibr, Will Harris, Daniel Cheng, AyeAye, Lei Zhang, tracing...@chromium.org, wfh+...@chromium.org, spang...@chromium.org, asvitki...@chromium.org, chromiumme...@microsoft.com

Attention needed from gate kibr

Will Harris added 1 comment

File base/metrics/field_trial_params.cc

Line 145, Patchset 13 (Latest): auto [it, inserted] = trial_groups.emplace(trial, group);

Lei Zhang . unresolved

I personally prefer:
```
bool inserted = some_container_call().second;
if (!inserted) {
   ...
}
```
Then there is no unused `it` variable.

Will Harris

driveby - you could use placeholder too

`auto [_, inserted] = ...`

e.g. https://source.chromium.org/search?q=%22auto%20%5B_%22&ss=chromium

Open in Gerrit

Related details

Attention is currently required from:

gate kibr

Submit Requirements:

Code-Coverage
Code-Owners
Code-Review
No-Unresolved-Comments
Review-Enforcement

Inspect html for hidden footers to help with email filtering. To unsubscribe visit settings.

Gerrit

satisfied_requirement

unsatisfied_requirement

open

diffy

gate kibr (Gerrit)

unread,

Mar 26, 2026, 11:30:42 PM (7 days ago) Mar 26

to Will Harris, Daniel Cheng, AyeAye, Lei Zhang, tracing...@chromium.org, wfh+...@chromium.org, spang...@chromium.org, asvitki...@chromium.org, chromiumme...@microsoft.com

Attention needed from Daniel Cheng, Lei Zhang and Will Harris

gate kibr added 3 comments

File base/metrics/field_trial_params.cc

Line 145, Patchset 13: auto [it, inserted] = trial_groups.emplace(trial, group);

Lei Zhang . resolved

I personally prefer:
```
bool inserted = some_container_call().second;
if (!inserted) {
   ...
}
```
Then there is no unused `it` variable.

Will Harris

driveby - you could use placeholder too
`auto [_, inserted] = ...`
e.g. https://source.chromium.org/search?q=%22auto%20%5B_%22&ss=chromium

gate kibr

Done, Thanks will

Line 156, Patchset 13: params[std::move(key)] = std::move(value);

Lei Zhang . resolved

Just combine with previous line.

gate kibr

Done

File base/scoped_add_feature_flags.cc

Line 88, Patchset 13: if (enable) {


    enabled_features_.emplace_back(std::move(feature_name));
  } else {
    disabled_features_.emplace_back(std::move(feature_name));
  }

Lei Zhang . resolved

Can simplify further:
```
auto& container = enable ? enabled_features_ : disabled_features_;
container.emplace_back(...);
```

gate kibr

Done

Open in Gerrit

Related details

Attention is currently required from:

Daniel Cheng
Lei Zhang
Will Harris

Submit Requirements:

Code-Coverage
Code-Owners
Code-Review

Review-Enforcement

Inspect html for hidden footers to help with email filtering. To unsubscribe visit settings.

Gerrit

satisfied_requirement

unsatisfied_requirement

open

diffy

Lei Zhang (Gerrit)

unread,

Mar 27, 2026, 1:37:59 PM (6 days ago) Mar 27

to gate kibr, Lei Zhang, Will Harris, Daniel Cheng, AyeAye, tracing...@chromium.org, wfh+...@chromium.org, spang...@chromium.org, asvitki...@chromium.org, chromiumme...@microsoft.com

Attention needed from Daniel Cheng, Will Harris and gate kibr

Lei Zhang voted

Code-Review	+1
Commit-Queue	+1

Open in Gerrit

Related details

Attention is currently required from:

Daniel Cheng
Will Harris
gate kibr

Submit Requirements:

Code-Coverage
Code-Owners
Code-Review
Review-Enforcement

Inspect html for hidden footers to help with email filtering. To unsubscribe visit settings.

Gerrit

satisfied_requirement

unsatisfied_requirement

open

diffy

Will Harris (Gerrit)

unread,

Mar 27, 2026, 7:54:33 PM (6 days ago) Mar 27

to gate kibr, Will Harris, Chromium LUCI CQ, Lei Zhang, Daniel Cheng, AyeAye, tracing...@chromium.org, wfh+...@chromium.org, spang...@chromium.org, asvitki...@chromium.org, chromiumme...@microsoft.com

Attention needed from Daniel Cheng and gate kibr

Will Harris voted and added 1 comment

Votes added by Will Harris

Code-Review

+1

1 comment

Patchset-level comments

File-level comment, Patchset 16 (Latest):

Will Harris . resolved

if lei is okay then I am okay too.

Open in Gerrit

Related details

Attention is currently required from:

Daniel Cheng
gate kibr

Submit Requirements:

Code-Coverage
Code-Owners

Code-Review
Review-Enforcement

Inspect html for hidden footers to help with email filtering. To unsubscribe visit settings.

Gerrit

satisfied_requirement

open

diffy

Daniel Cheng (Gerrit)

unread,

Mar 28, 2026, 1:26:55 AM (6 days ago) Mar 28

to gate kibr, Daniel Cheng, Will Harris, Chromium LUCI CQ, Lei Zhang, AyeAye, tracing...@chromium.org, wfh+...@chromium.org, spang...@chromium.org, asvitki...@chromium.org, chromiumme...@microsoft.com

Attention needed from gate kibr

Daniel Cheng voted Commit-Queue+2

Commit-Queue

+2

Open in Gerrit

Related details

Attention is currently required from:

gate kibr

Submit Requirements:

Code-Coverage
Code-Owners
Code-Review
Review-Enforcement

Inspect html for hidden footers to help with email filtering. To unsubscribe visit settings.

Gerrit

satisfied_requirement

open

diffy

Daniel Cheng (Gerrit)

unread,

Mar 28, 2026, 1:27:02 AM (6 days ago) Mar 28

to gate kibr, Daniel Cheng, Will Harris, Chromium LUCI CQ, Lei Zhang, AyeAye, tracing...@chromium.org, wfh+...@chromium.org, spang...@chromium.org, asvitki...@chromium.org, chromiumme...@microsoft.com

Attention needed from gate kibr

Daniel Cheng voted Code-Review+1

Code-Review

+1

Open in Gerrit

Related details

Attention is currently required from:

gate kibr

Submit Requirements:

Code-Coverage
Code-Owners
Code-Review
Review-Enforcement

Inspect html for hidden footers to help with email filtering. To unsubscribe visit settings.

Gerrit

satisfied_requirement

open

diffy

Chromium LUCI CQ (Gerrit)

unread,

Mar 28, 2026, 1:41:28 AM (6 days ago) Mar 28

to gate kibr, Daniel Cheng, Will Harris, Lei Zhang, AyeAye, tracing...@chromium.org, wfh+...@chromium.org, spang...@chromium.org, asvitki...@chromium.org, chromiumme...@microsoft.com

Chromium LUCI CQ submitted the change

Change information

Commit message:

Use emplace and std::move to optimize

- Replace find()+insert() pattern with emplace()
- Use std::move() + emplace
- Use iterators when erasing

Change-Id: I361b379d1a383bd6126bb90fd069d2dca7d31afb

Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/7688742

Commit-Queue: Daniel Cheng <dch...@chromium.org>

Reviewed-by: Lei Zhang <the...@chromium.org>

Reviewed-by: Will Harris <w...@chromium.org>

Reviewed-by: Daniel Cheng <dch...@chromium.org>

Cr-Commit-Position: refs/heads/main@{#1606630}

Files:

M base/metrics/field_trial_params.cc
M base/scoped_add_feature_flags.cc
M base/supports_user_data.cc
M base/trace_event/trace_config.cc

Change size: S

Delta: 4 files changed, 9 insertions(+), 15 deletions(-)

Branch: refs/heads/main

Submit Requirements:

Code-Review: +1 by Will Harris, +1 by Daniel Cheng, +1 by Lei Zhang

Open in Gerrit

Inspect html for hidden footers to help with email filtering. To unsubscribe visit settings.

Gerrit

open

diffy

satisfied_requirement

Reply all

Reply to author

Forward

Use emplace and std::move to optimize [chromium/src : main]

Daniel Cheng (Gerrit)

Daniel Cheng voted Code-Review+1

Related details

gate kibr (Gerrit)

gate kibr added 1 comment

Related details

Lei Zhang (Gerrit)

Lei Zhang added 3 comments

Related details

Will Harris (Gerrit)

Will Harris added 1 comment

Related details

gate kibr (Gerrit)

gate kibr added 3 comments

Related details

Lei Zhang (Gerrit)

Lei Zhang voted

Related details

Will Harris (Gerrit)

Will Harris voted and added 1 comment

Votes added by Will Harris

1 comment

Related details

Daniel Cheng (Gerrit)

Daniel Cheng voted Commit-Queue+2

Related details

Daniel Cheng (Gerrit)

Daniel Cheng voted Code-Review+1

Related details

Chromium LUCI CQ (Gerrit)

Chromium LUCI CQ submitted the change

Change information