Chromium side plumbing for enabling fixed root background compositing.

Chromium side plumbing for enabling fixed root background compositing.

Adds --enable-accelerated-fixed-root-background and related plumbing.

Depends on wkb.ug/112865

TBR=sky@chromium.org

BUG=180885
Committed: https://src.chromium.org/viewvc/chrome?view=rev&revision=210416

[Ian Vollick, 2013-03-21 02:03:09]

+jamesr for webkit/
+piman for content/
+sky for chrome/

[jamesr, 2013-03-21 02:04:47]

lgtm

[jamesr, 2013-03-21 02:05:59]

Either on this patch or on the WebKit one we need to make sure we aren't
creating extra compositing layers on Android which doesn't support
background-attachment: fixed.

[piman, 2013-03-21 02:12:36]

lgtm

[Ian Vollick, 2013-03-22 17:47:10]

+aelias

On 2013/03/21 02:05:59, jamesr wrote:
> Either on this patch or on the WebKit one we need to make sure we aren't
> creating extra compositing layers on Android which doesn't support
> background-attachment: fixed.

It's my understanding that once we have support for putting
background-attachment: fixed backgrounds on separate layers, Android plans on
allowing background-attachment: fixed. Alex, please correct me if I've got that
wrong.

In any case, this code should do nothing unless enabled with this flag, so
Android can choose not to enable the feature if it causes problems.

[aelias_OOO_until_Jul13, 2013-03-22 20:33:35]

Yes, we decided it to turn it off because we couldn't handle all the invalidates
when it wasn't in a layer.  We'll re-evaluate if we can turn it on once it is in
a layer.

[Ian Vollick, 2013-06-06 17:21:44]

On 2013/03/22 20:33:35, aelias wrote:
> Yes, we decided it to turn it off because we couldn't handle all the
invalidates
> when it wasn't in a layer.  We'll re-evaluate if we can turn it on once it is
in
> a layer.

I've updated the settings plumbing to match what we're doing with other
high-DPI-only flags like --enable-compositing-for-transitions and
--enable-fixed-position-compositing:
 - The setting can be controlled via about:flags
 - The setting is enabled by default on high-DPI

[aelias_OOO_until_Jul13, 2013-06-06 19:18:45]

On 2013/06/06 17:21:44, vollick wrote:
>  - The setting is enabled by default on high-DPI

OK, that implies enabling it by default on Android.  So we should probably at
least smoke test it on Android devices.  Is the feature complete now?

[Ian Vollick, 2013-07-03 18:51:46]

On 2013/06/06 19:18:45, aelias wrote:
> On 2013/06/06 17:21:44, vollick wrote:
> >  - The setting is enabled by default on high-DPI
> 
> OK, that implies enabling it by default on Android.  So we should probably at
> least smoke test it on Android devices.  Is the feature complete now?

I think I've confirmed that the feature works on Android. I visited this page
(http://jsfiddle.net/hPFC8/embedded/result/) in content_shell on my Nexus 7 with
paint rects visible, and we weren't repainting the page on scroll updates. The
page stays put when pinch-zooming which, I believe, is the desired behavior.

[Ian Vollick, 2013-07-03 18:52:23]

On 2013/07/03 18:51:46, vollick wrote:
> On 2013/06/06 19:18:45, aelias wrote:
> > On 2013/06/06 17:21:44, vollick wrote:
> > >  - The setting is enabled by default on high-DPI
> > 
> > OK, that implies enabling it by default on Android.  So we should probably
at
> > least smoke test it on Android devices.  Is the feature complete now?
> 
> I think I've confirmed that the feature works on Android. I visited this page
> (http://jsfiddle.net/hPFC8/embedded/result/) in content_shell on my Nexus 7
with
> paint rects visible, and we weren't repainting the page on scroll updates. The
> page stays put when pinch-zooming which, I believe, is the desired behavior.

Sorry, that should have read "The background stays put..." Sorry for the spam.

[aelias_OOO_until_Jul13, 2013-07-08 01:03:30]

OK, lgtm!  We're quite far from M30 branch point so I'm fine with trying to turn
this on for Android (since we do want the feature).

[commit-bot: I haz the power, 2013-07-08 03:46:13]

CQ is trying da patch. Follow status at
https://chromium-status.appspot.com/cq/vollick@chromium.org/12544030/16001

[commit-bot: I haz the power, 2013-07-08 04:20:43]

Sorry for I got bad news for ya.
Compile failed with a clobber build on linux_chromeos.
http://build.chromium.org/p/tryserver.chromium/buildstatus?builder=linux_chro...
Your code is likely broken or HEAD is junk. Please ensure your
code is not broken then alert the build sheriffs.
Look at the try server FAQ for more details.

[commit-bot: I haz the power, 2013-07-08 17:22:12]

CQ is trying da patch. Follow status at
https://chromium-status.appspot.com/cq/vollick@chromium.org/12544030/16001

[commit-bot: I haz the power, 2013-07-08 17:24:03]

Step "update" is always a major failure.
Look at the try server FAQ for more details.
http://build.chromium.org/p/tryserver.chromium/buildstatus?builder=mac_rel&nu...

[commit-bot: I haz the power, 2013-07-08 19:36:37]

CQ is trying da patch. Follow status at
https://chromium-status.appspot.com/cq/vollick@chromium.org/12544030/16001

[commit-bot: I haz the power, 2013-07-08 21:07:26]

Change committed as 210416