Any workarounds?

I have a similar problem - offscreen iframe does not render fully and interaction does not paint it properly either, SVG gets half rendered for example, resize or scroll forces iframe layer to work properly. Will try to create reproduction steps.

Happens in m50 and trunk. This seems like a pretty serious regression. Assigning to chrishtr@ for triage.

It's not clear to me that c#1 is the same issue. How do you know that something offscreen is painted or not? Could you please clarify the steps to reproduce your problem? 

Sorry for being not clear with c#1.

Here's the current repro case failing with Chrome 49 (OS X only) - https://dl.dropboxusercontent.com/u/463359/regression.html

Also failing on Canary (v51).

Steps:
1) Click "Open" button - <iframe> is transformed to correct position but not painted.
2) Click in the vicinity of "Open" button or resize paints the iframe


I'm trying to get it narrowed down as it is connected to my frame contents - don't know yet what.
Also disabling web security with flag helps too.

This is a subsequence caching bug. Digging some more to find the place where
we are failing to set needsRepaint.

It's a bug when transitioning from shouldSuppressPaintingLayer (FOUC-avoidance
mode) to regular painting mode. This doc gives some more background, but
the fix should be to mark needsRepaint when exiting that mode.

https://docs.google.com/document/d/1waQggCtPb44gwTp8PK5iz4B-YTiSOSBqbqtbopNrxNA/edit?pref=2&pli=1#

This bug has been marked as M49 Stable blocker and We're in process of cutting Stable RC today. So wanted to know if the fix/merge will be safe to M49 and when can we expect the fix?

Per chat with chrishtr@, this is M50 Stable blocker NOT M49. 
Bug was originally reported for M49, so not removing "M-49" label for now. Shruthi, please remove M-49" label if you think it is ok to do so.

I removed M-49 for clarity. However, the bug does appear in M49, and it's still
possible we will need to merge this to M-49 as it may be a severe issue. :(

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/27c25394291c192a6a10a83f2bae1c1539feb993

commit 27c25394291c192a6a10a83f2bae1c1539feb993
Author: chrishtr <chrishtr@chromium.org>
Date: Wed Mar 23 04:32:03 2016

Disable subsequence caching when didLayoutWithPendingStylesheets is true.

BUG= 593758 

Review URL: https://codereview.chromium.org/1823353003

Cr-Commit-Position: refs/heads/master@{#382791}

[modify] https://crrev.com/27c25394291c192a6a10a83f2bae1c1539feb993/third_party/WebKit/Source/core/paint/PaintLayerPainter.cpp
[modify] https://crrev.com/27c25394291c192a6a10a83f2bae1c1539feb993/third_party/WebKit/Source/web/tests/DocumentLoadingRenderingTest.cpp

Your change meets the bar and is auto-approved for M50 (branch: 2661)

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/91283f70477be7d059454b89fb7839dbd465130d

commit 91283f70477be7d059454b89fb7839dbd465130d
Author: Chris Harrelson <chrishtr@chromium.org>
Date: Thu Mar 24 17:07:55 2016

Disable subsequence caching when didLayoutWithPendingStylesheets is true.

BUG= 593758 

Review URL: https://codereview.chromium.org/1823353003

Cr-Commit-Position: refs/heads/master@{#382791}
(cherry picked from commit 27c25394291c192a6a10a83f2bae1c1539feb993)

Review URL: https://codereview.chromium.org/1827043003 .

Cr-Commit-Position: refs/branch-heads/2661@{#376}
Cr-Branched-From: ef6f6ae5e4c96622286b563658d5cd62a6cf1197-refs/heads/master@{#378081}

[modify] https://crrev.com/91283f70477be7d059454b89fb7839dbd465130d/third_party/WebKit/Source/core/paint/PaintLayerPainter.cpp
[modify] https://crrev.com/91283f70477be7d059454b89fb7839dbd465130d/third_party/WebKit/Source/web/tests/DocumentLoadingRenderingTest.cpp

It would be really good to merge this to 49 if possible. I'm sure sites are affected.

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/7e84cd06b975aa722a15d60cd0beed523bfdf8bc

commit 7e84cd06b975aa722a15d60cd0beed523bfdf8bc
Author: trchen <trchen@chromium.org>
Date: Thu Mar 24 20:59:35 2016

Revert of Disable subsequence caching when didLayoutWithPendingStylesheets is true. (patchset #1 id:1 of https://codereview.chromium.org/1827043003/ )

Reason for revert:
Build failed. The branch was before we renamed the getters from property to getProperty.

Original issue's description:
> Disable subsequence caching when didLayoutWithPendingStylesheets is true.
>
> BUG= 593758 
>
> Review URL: https://codereview.chromium.org/1823353003
>
> Cr-Commit-Position: refs/heads/master@{#382791}
> (cherry picked from commit 27c25394291c192a6a10a83f2bae1c1539feb993)
>
> Committed: https://chromium.googlesource.com/chromium/src/+/91283f70477be7d059454b89fb7839dbd465130d

TBR=chrishtr@chromium.org
# Skipping CQ checks because original CL landed less than 1 days ago.
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG= 593758 

Review URL: https://codereview.chromium.org/1833003002

Cr-Commit-Position: refs/branch-heads/2661@{#382}
Cr-Branched-From: ef6f6ae5e4c96622286b563658d5cd62a6cf1197-refs/heads/master@{#378081}

[modify] https://crrev.com/7e84cd06b975aa722a15d60cd0beed523bfdf8bc/third_party/WebKit/Source/core/paint/PaintLayerPainter.cpp
[modify] https://crrev.com/7e84cd06b975aa722a15d60cd0beed523bfdf8bc/third_party/WebKit/Source/web/tests/DocumentLoadingRenderingTest.cpp

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/90353a6a03badd7df0bc8c2af004397a72e44ab9

commit 90353a6a03badd7df0bc8c2af004397a72e44ab9
Author: trchen <trchen@chromium.org>
Date: Thu Mar 24 21:47:41 2016

Disable subsequence caching when didLayoutWithPendingStylesheets is true.

BUG= 593758 
Review URL: https://codereview.chromium.org/1823353003

Cr-Commit-Position: refs/heads/master@{#382791}
(cherry picked from commit 27c25394291c192a6a10a83f2bae1c1539feb993)

TBR=chrishtr@chromium.org
NOTRY=true
NOPRESUBMIT=true

Review URL: https://codereview.chromium.org/1828303004

Cr-Commit-Position: refs/branch-heads/2661@{#384}
Cr-Branched-From: ef6f6ae5e4c96622286b563658d5cd62a6cf1197-refs/heads/master@{#378081}

[modify] https://crrev.com/90353a6a03badd7df0bc8c2af004397a72e44ab9/third_party/WebKit/Source/core/paint/PaintLayerPainter.cpp
[modify] https://crrev.com/90353a6a03badd7df0bc8c2af004397a72e44ab9/third_party/WebKit/Source/web/tests/DocumentLoadingRenderingTest.cpp

[Automated comment] Request affecting a post-stable build (M49), manual review required.

Had a group chat with trchen@ & sshruthi@ and as per trchen@, this is a safe merge .The build error was due to simple variable renaming (Comment #20). Also the change was baked in canary as well. So approving merge to M49 branch 2623. Please merge ASAP.

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/78fbeb99c97eefd89a91841db74ea212820f7c50

commit 78fbeb99c97eefd89a91841db74ea212820f7c50
Author: trchen <trchen@chromium.org>
Date: Fri Mar 25 22:17:02 2016

Disable subsequence caching when didLayoutWithPendingStylesheets is true.

BUG= 593758 
Review URL: https://codereview.chromium.org/1823353003

Cr-Commit-Position: refs/heads/master@{#382791}
(cherry picked from commit 27c25394291c192a6a10a83f2bae1c1539feb993)

TBR=chrishtr@chromium.org
NOTRY=true
NOPRESUBMIT=true

Review URL: https://codereview.chromium.org/1833043007

Cr-Commit-Position: refs/branch-heads/2623@{#656}
Cr-Branched-From: 92d77538a86529ca35f9220bd3cd512cbea1f086-refs/heads/master@{#369907}

[modify] https://crrev.com/78fbeb99c97eefd89a91841db74ea212820f7c50/third_party/WebKit/Source/core/paint/PaintLayerPainter.cpp
[modify] https://crrev.com/78fbeb99c97eefd89a91841db74ea212820f7c50/third_party/WebKit/Source/web/tests/DocumentLoadingRenderingTest.cpp

Verified the merge on the latest M-49(49.0.2623.110/ branch-heads/2623@{#657}) on Windows-7, Mac OS 10.11.3 and Linux Ubuntu 14.04. This is working as intended and input boxes are rendered as soon as landing on http://torpedro.com/other/chrome-iframe-bug/test.html.

Thank you!

Works fine on 50.0.2661.57 as well, across Windows-7, Mac OS 10.11.3 and Linux Ubuntu 14.04. Adding verified label for M-50 also.