Bug 75116 – [chromium] Add support for layer tree debugging

• Status: RESOLVED
• Resolution: WONTFIX
• Component: New Bugs

[chromium] Add support for creating dotty-friendly layer tree dumps

Created attachment 120371 [details]
Patch

[WebKit Review Bot]

Please wait for approval from [e-mail] before submitting because this patch contains changes to the Chromium public API.

[James Robinson]

Comment on attachment 120371 [details]
Patch

View in context: https://bugs.webkit.org/attachment.cgi?id=120371&action=review

What is dotty?

> Source/WebCore/ChangeLog:8
> +        No new tests. (OOPS!)

this won't blend

(In reply to comment #3)
> (From update of attachment 120371 [details])
> View in context: https://bugs.webkit.org/attachment.cgi?id=120371&action=review
> 
> What is dotty?

It's a graph viz tool. The hope was that we could generate a graph of the webkit layers for debugging purposes. Also, I should have said 'in the dot language' rather than 'dotty-friendly' http://en.wikipedia.org/wiki/DOT_language

> 
> > Source/WebCore/ChangeLog:8
> > +        No new tests. (OOPS!)
> 
> this won't blend

Does this mean a test is required or that there were merge conflicts? I'm pretty sure you meant the former, but I thought I'd double-check, just in case.

[Peter Kotwicz]

Ping

[James Robinson]

I'm not sure this is really worth having, to be honest.

Created attachment 124559 [details]
Patch

[Peter Kotwicz]

Created attachment 130513 [details]
Patch

[WebKit Review Bot]

Please wait for approval from [e-mail], [e-mail] or [e-mail] before submitting because this patch contains changes to the Chromium platform API.

[James Robinson]

Comment on attachment 130513 [details]
Patch

It seems like you attached this patch to the wrong bug, no?

I'm not at all excited about adding a synchronous cross-thread commit flow unless it's super super valuable.  There are lots of subtle threading/ordering bugs to flush out to make this work well.  What is this needed for?

[Peter Kotwicz]

Sorry for taking so long to reply.
I want to use this for displaying the impl layertree in WebUI. On the chromium side, I have created a WebUI page which will display the layer trees for both the browser and the webkit layertree.
This is similar to the flags --show-composited-layer-tree and --ui-show-layer-tree
The advantage of doing this in WebUI are:
1) The layertree is scrollable (the browser layer tree is large)
2) We can explore with interesting ways of showing the layertree data if useful

I believe that something like this could be useful for people starting out with WebKit.

I chose to display the impl layer tree because we were already generating the Webkit layer tree.
One option would be to generate the non impl layer tree in LayerChromium and use that. wjmaclean would this still be useful?

[W. James MacLean]

(In reply to comment #11)
> Sorry for taking so long to reply.
> I want to use this for displaying the impl layertree in WebUI. On the chromium side, I have created a WebUI page which will display the layer trees for both the browser and the webkit layertree.
> This is similar to the flags --show-composited-layer-tree and --ui-show-layer-tree
> The advantage of doing this in WebUI are:
> 1) The layertree is scrollable (the browser layer tree is large)
> 2) We can explore with interesting ways of showing the layertree data if useful
> 
> I believe that something like this could be useful for people starting out with WebKit.
> 
> I chose to display the impl layer tree because we were already generating the Webkit layer tree.
> One option would be to generate the non impl layer tree in LayerChromium and use that. wjmaclean would this still be useful?

Having seen this in action, I think it will be useful for large layer trees, and esp. in Aura development it's nice being able to have the layer tree displayed in a separate window from the page being debugged. The benefit of being able to make display more informative by showing additional information seems pretty useful.

Ultimately it would be nice to see both main- and impl-thread trees (although these need not be in the same window). In the short term I'm not sure which tree is more important to display (or if there's even an answer to that question).

[Stephen Chenney]

https://code.google.com/p/chromium/issues/detail?id=230820