RESOLVED FIXED 92469
[chromium] CCLayerTreeHost placeholder scissor should be deviceViewportSize instead of viewportSize 
https://bugs.webkit.org/show_bug.cgi?id=92469
Summary [chromium] CCLayerTreeHost placeholder scissor should be deviceViewportSize i...
Shawn Singh
Reported 2012-07-27 00:42:43 PDT
http://code.google.com/p/chromium/issues/detail?id=139005 After tracing the problem from missing tiles --> skipped paints --> bad occlusion --> bad scissor rect, it finally showed up that we are accidentally setting the placeholder scissorRect to the viewportSize. As I understand, the space of the scissorRect is expected to be in the pixel accurate content space of the targetSurface; and for this main-thread placeholder default scissor, that means we should have been using deviceViewportSize instead of viewportSize. It does indeed fix the flickering issue that showed up suddenly on canary. Dear Reviewers: if you wish to land it right away, please go ahead, and feel free to create another bug on me to add a unit test. If you prefer to wait and land this after unit test is created, I'll work on it right away to get this landed soon.
Attachments
Patch (1.87 KB, patch)
2012-07-27 00:53 PDT, Shawn Singh 		no flags
DetailsFormatted DiffDiff
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Shawn Singh
Comment 1 2012-07-27 00:53:30 PDT
Created attachment 154868 [details] Patch
Dana Jansens
Comment 2 2012-07-27 08:32:33 PDT
Comment on attachment 154868 [details] Patch good catch. lgtm
Adrienne Walker
Comment 3 2012-07-27 08:33:57 PDT
The code change looks right to me, but if you can get a test in today, let's land them together.
Adrienne Walker
Comment 4 2012-07-27 14:05:54 PDT
Comment on attachment 154868 [details] Patch R=me. After some conversation with Shawn, I'm not sure that there's a really good way to test this without some serious refactoring of how CCLayerTreeHost works. This seems clearly like the right fix, so let's just land it.
WebKit Review Bot
Comment 5 2012-07-27 15:04:32 PDT
Comment on attachment 154868 [details] Patch Clearing flags on attachment: 154868 Committed r123921: <http://trac.webkit.org/changeset/123921>
WebKit Review Bot
Comment 6 2012-07-27 15:04:36 PDT
All reviewed patches have been landed. Closing bug.
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