Get windowless plugins working when accelerated compositing is turned on.

Get windowless plugins working when accelerated compositing is turned on by copying the buffers using skia instead of OS specific ways that need the platform device.

Also remove the code that kept the background buffer in sync with plugins since it's not necessary anymore. Looks like Flash and Silverlight support this correctly now.
Committed: https://src.chromium.org/viewvc/chrome?view=rev&revision=167042

[jam, 2012-11-09 19:02:25]

ping

https://codereview.chromium.org/11361170/diff/9003/content/renderer/webplugin...
File content/renderer/webplugin_delegate_proxy.cc (right):

https://codereview.chromium.org/11361170/diff/9003/content/renderer/webplugin...
content/renderer/webplugin_delegate_proxy.cc:787: &src_rect,
gfx::RectToSkRect(offset_rect));
btw I found that somehow this isn't working on Linux. any idea? On Win/Mac this
works fine by copying the current page's data to the background canvas. On
Linux, this seems to not do anything.

[piman, 2012-11-09 19:27:02]

+reveman who has looked at windowless NPAPI issues with compositing.

https://codereview.chromium.org/11361170/diff/9003/content/renderer/webplugin...
File content/renderer/webplugin_delegate_proxy.cc (left):

https://codereview.chromium.org/11361170/diff/9003/content/renderer/webplugin...
content/renderer/webplugin_delegate_proxy.cc:838: #if defined(OS_WIN)
Awesome thanks for removing this horrible per-platform code.

https://codereview.chromium.org/11361170/diff/9003/content/renderer/webplugin...
File content/renderer/webplugin_delegate_proxy.cc (right):

https://codereview.chromium.org/11361170/diff/9003/content/renderer/webplugin...
content/renderer/webplugin_delegate_proxy.cc:676:
background_store_.canvas->drawColor(SK_ColorWHITE);
How about writing transparent pixels? If the plugin is transparent, you have a
shot at compositing it correctly.

https://codereview.chromium.org/11361170/diff/9003/content/renderer/webplugin...
content/renderer/webplugin_delegate_proxy.cc:779: // but there's nothing we can
do about that. This is mostly mitigiated
typo: mitigated

https://codereview.chromium.org/11361170/diff/9003/content/renderer/webplugin...
content/renderer/webplugin_delegate_proxy.cc:787: &src_rect,
gfx::RectToSkRect(offset_rect));
On 2012/11/09 19:02:25, John Abd-El-Malek wrote:
> btw I found that somehow this isn't working on Linux. any idea? On Win/Mac
this
> works fine by copying the current page's data to the background canvas. On
> Linux, this seems to not do anything.

I'm not sure specifically, but I was going to mention that we want to check what
happens for recording canvas (either with --enable-per-tile-painting or
--enable-accelerated-drawing). They don't give you (directly) access to the
underlying pixels.
It may be related, but I don't think it's on by default on linux though.

https://codereview.chromium.org/11361170/diff/9003/content/renderer/webplugin...
content/renderer/webplugin_delegate_proxy.cc:829: int row_byte_size =
rect.width() * page.bytesPerPixel();
This can get tricky with CSS transforms, in particular 3D ones. I think we need
extra clipping (once transformed, the rect may be outside the page bounds). See
e.g. crbug.com/137623

[jam, 2012-11-09 22:50:24]

https://codereview.chromium.org/11361170/diff/9003/content/renderer/webplugin...
File content/renderer/webplugin_delegate_proxy.cc (right):

https://codereview.chromium.org/11361170/diff/9003/content/renderer/webplugin...
content/renderer/webplugin_delegate_proxy.cc:676:
background_store_.canvas->drawColor(SK_ColorWHITE);
On 2012/11/09 19:27:03, piman wrote:
> How about writing transparent pixels? If the plugin is transparent, you have a
> shot at compositing it correctly.

Thanks, actually trying this out shows that NPAPI Flash and Silverlight now
support transparency correctly and don't need the page text to be present :)
This means we don't need any of this code, so I've gone ahead and purged it.

[piman, 2012-11-09 23:50:48]

Well, that makes it easy. Very nice.
LGTM