Performance profiling support for web

[HeinrichJanzing]

Is there an existing issue for this?

• I have searched the existing issues
• I have read the guide to filing a bug

Use case

We are primarily targeting the web platform with Flutter. While other platforms benefit from the very helpful Performance View, it states that developers targeting web should be happy with the Chrome dev tools (and stops there).

The Chrome dev tools will not give you any insights specific to Flutter, or at least not without manual digging. This includes many things listed in the docs for the Performance View, like quickly seeing the most problematic phase (Build/Layout/Raster) and finding out what widget is (most) responsible for it. It's all just "Scripting".

Flutter web typically performs less than native apps. I would say that makes good performance analysis tools more important than for native platforms.

Proposal

Can we make performance analysis for web easier? Ideally, the same tools you have for native apps are made available. Failing that, we need guidance on how to use the Chrome dev tools to achieve the same.

[yjbanov]

Moved it to team-tool because it sounds the closest to Flutter DevTools, but feel free to relabel if this is wrong.

[eliasyishak]

FYI if you can provide any additional context @kenzieschmoll