Bug 65210 - [chromium] Remove viewport clear from release builds
Summary: [chromium] Remove viewport clear from release builds
Status: RESOLVED WONTFIX
Alias: None
Product: WebKit
Classification: Unclassified
Component: New Bugs (show other bugs)
Version: 528+ (Nightly build)
Hardware: Unspecified Unspecified
: P2 Normal
Assignee: James Robinson
URL:
Keywords:
Depends on:
Blocks:
 
Reported: 2011-07-26 15:31 PDT by James Robinson
Modified: 2013-04-11 14:49 PDT (History)
7 users (show)

See Also:


Attachments
Patch (1.86 KB, patch)
2011-07-26 15:55 PDT, James Robinson
no flags Details | Formatted Diff | Diff

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Description James Robinson 2011-07-26 15:31:30 PDT
[chromium] Remove viewport clear from release builds
Comment 1 James Robinson 2011-07-26 15:55:41 PDT
Created attachment 102067 [details]
Patch
Comment 2 Kenneth Russell 2011-07-26 17:32:19 PDT
Comment on attachment 102067 [details]
Patch

Hmm. Debug builds are so slow that it's unlikely we will do extensive testing with them. But I'll leave this decision up to those working on the compositor.
Comment 3 James Robinson 2011-07-26 17:39:06 PDT
We do run the compositing tests in debug, at least.
Comment 4 WebKit Review Bot 2011-07-26 19:14:55 PDT
Comment on attachment 102067 [details]
Patch

Rejecting attachment 102067 [details] from commit-queue.

Failed to run "['./Tools/Scripts/webkit-patch', '--status-host=queues.webkit.org', '--bot-id=ec2-cq-01', '--port..." exit_code: 1

Last 500 characters of output:
0e94b75603c487eee0ba355e40fcb6b01c81ffa8
r91810 = 851bbe5a9502994f015ea8746c3ec847fc50b2b4
Done rebuilding .git/svn/refs/remotes/origin/master/.rev_map.268f45cc-cd09-0410-ab3c-d52691b4dbfc
First, rewinding head to replay your work on top of it...
Fast-forwarded master to refs/remotes/origin/master.
Updating chromium port dependencies using gclient...

________ running '/usr/bin/python gyp_webkit' in '/mnt/git/webkit-commit-queue/Source/WebKit/chromium'
Updating webkit projects from gyp files...

Full output: http://queues.webkit.org/results/9245650
Comment 5 James Robinson 2011-07-26 19:23:55 PDT
Gah, I misformatted the ChangeLog again.  D'oh!
Comment 6 James Robinson 2011-07-26 19:28:20 PDT
Committed r91812: <http://trac.webkit.org/changeset/91812>
Comment 7 Adrienne Walker 2011-07-26 20:18:33 PDT
Reverted r91812 for reason:

Breaks

Committed r91821: <http://trac.webkit.org/changeset/91821>
Comment 8 James Robinson 2011-07-27 13:39:14 PDT
So as it turns out, this clear was the only thing ensuring that the root layer's alpha channel was fully opaque.  We mask out alpha writes when drawing the root layer so on the mac bot the alpha channel was in an undefined state.

I think a better approach is to clear the default render surface whenever it is created or resized, instead of every frame.  I'll look into this if I get a chance.  We are paying a lot of bandwidth for this clear currently.