Specify that widget rebuilds is only available when running in debug-mode

[elliette]

Currently when you run your app in profile-mode, the performance panel shows a disabled checkbox that makes it seem like it should be possible to "count widget builds" (see screenshot below)

In actuality, "count widget builds" relies on the trackRebuildDirtyWidgets service extension, which uses debugOnRebuildDirtyWidget. This is only available in debug-mode: https://github.com/flutter/flutter/blob/f9e809913240552c391bf31b1cfdbdf410224d8c/packages/flutter/lib/src/widgets/debug.dart#L59

Instead of "To see widget rebuilds for Flutter frames, enable CountWidgetRebuilds", we should remove the checkbox and update the text to say "Rebuild information not available for this frame. Widget rebuild counts are only available when running an app in debug-mode."

[Bingtagui404]

Hi, I'd like to take this one.

I think the issue is the Performance panel shows a disabled "Count widget builds" checkbox in profile-mode with no explanation of why it's disabled, when in fact this feature relies on trackRebuildDirtyWidgets / debugOnRebuildDirtyWidget which are only available in debug-mode.

My plan is to remove the disabled checkbox and update the text to say "Rebuild information not available for this frame. Widget rebuild counts are only available when running an app in debug-mode." as suggested in the issue.

Please let me know if you'd prefer a different approach.

[Bingtagui404]

Sorry, I won't be able to work on this due to personal reasons. Feel free to reassign it to someone else.