Update scrollbars from FrameView::show.

Update scrollbars from FrameView::show.

When an iframe is hidden, FrameView::dispose is called to detach the
FrameView, which has the effect of destroying its scrollbars.  When
the iframe is re-shown, it needs to recreate its scrollbars.

Note that this bug does not happen with root layer scrolling
enabled.

BUG=623280
R=skobes@chromium.org

[skobes, 2016-07-08 14:32:12]

Are you saying a FrameView is reused after calling dispose() on it?  That seems
crazy.

We should either not dispose() the FrameView when it is hidden, or create a new
FrameView when it comes back.

[szager1, 2016-07-08 20:31:45]

On 2016/07/08 14:32:12, skobes wrote:
> Are you saying a FrameView is reused after calling dispose() on it?  That
seems
> crazy.
> 
> We should either not dispose() the FrameView when it is hidden, or create a
new
> FrameView when it comes back.

I tried a different patch that doesn't dispose() the FrameView, but it broke
some tests.

At this point, I'm inclined to either land the first version of the patch, or
mark the bug as block on root layer scrolling.  I'm not inclined to pursue a fix
that eliminates the call to dispose(), as it seems to be working fine in
practice.

[skobes, 2016-07-08 21:28:15]

Patch Set 1 lgtm but can you file a bug to make HTMLFrameOwnerElement stop
reusing disposed FrameViews?

https://codereview.chromium.org/2129033002/diff/1/third_party/WebKit/LayoutTe...
File third_party/WebKit/LayoutTests/fast/frames/iframe-hide-show-scrollbars.html
(right):

https://codereview.chromium.org/2129033002/diff/1/third_party/WebKit/LayoutTe...
third_party/WebKit/LayoutTests/fast/frames/iframe-hide-show-scrollbars.html:8:
<iframe srcdoc="<style>body{margin:0px}</style>bananas bananas bananas bananas
bananas bananas bananas bananas bananas bananas "></iframe>
This can be less bananas with body{height:1000px}.

[szager1, 2016-07-08 21:53:25]

On 2016/07/08 21:28:15, skobes wrote:
> Patch Set 1 lgtm but can you file a bug to make HTMLFrameOwnerElement stop
> reusing disposed FrameViews?

Done: https://bugs.chromium.org/p/chromium/issues/detail?id=626810

[szager1, 2016-07-08 21:53:30]

https://codereview.chromium.org/2129033002/diff/1/third_party/WebKit/LayoutTe...
File third_party/WebKit/LayoutTests/fast/frames/iframe-hide-show-scrollbars.html
(right):

https://codereview.chromium.org/2129033002/diff/1/third_party/WebKit/LayoutTe...
third_party/WebKit/LayoutTests/fast/frames/iframe-hide-show-scrollbars.html:8:
<iframe srcdoc="<style>body{margin:0px}</style>bananas bananas bananas bananas
bananas bananas bananas bananas bananas bananas "></iframe>
On 2016/07/08 21:28:15, skobes wrote:
> This can be less bananas with body{height:1000px}.

I like bananas (because they have no bones).

[szager1, 2016-07-08 21:54:39]

The CQ bit was checked by szager@chromium.org

[szager1, 2016-07-08 21:54:40]

The patchset sent to the CQ was uploaded after l-g-t-m from skobes@chromium.org
Link to the patchset: https://codereview.chromium.org/2129033002/#ps40001
(title: "revert to patch set 1")

[commit-bot: I haz the power, 2016-07-08 21:55:22]

CQ is trying da patch. Follow status at
 
https://chromium-cq-status.appspot.com/v2/patch-status/codereview.chromium.or...

[commit-bot: I haz the power, 2016-07-08 23:13:44]

The CQ bit was unchecked by commit-bot@chromium.org

[commit-bot: I haz the power, 2016-07-08 23:13:46]

Try jobs failed on following builders:
  linux_chromium_rel_ng on master.tryserver.chromium.linux (JOB_FAILED,
http://build.chromium.org/p/tryserver.chromium.linux/builders/linux_chromium_...)

[skobes, 2017-08-10 21:34:00]

Description was changed from

==========
Update scrollbars from FrameView::show.

When an iframe is hidden, FrameView::dispose is called to detach the
FrameView, which has the effect of destroying its scrollbars.  When
the iframe is re-shown, it needs to recreate its scrollbars.

Note that this bug does not happen with root layer scrolling
enabled.

BUG=623280
R=skobes@chromium.org
==========

to

==========
Update scrollbars from FrameView::show.

When an iframe is hidden, FrameView::dispose is called to detach the
FrameView, which has the effect of destroying its scrollbars.  When
the iframe is re-shown, it needs to recreate its scrollbars.

Note that this bug does not happen with root layer scrolling
enabled.

BUG=623280
R=skobes@chromium.org
==========

[skobes, 2017-08-10 21:34:01]

skobes@chromium.org changed reviewers:
- skobes@chromium.org