Drop the backbuffer on hidden tabs on GLX image transport.

Drop the backbuffer on hidden tabs on GLX image transport.

This saves VRAM usage when multiple accelerated tabs are open by dropping the backbuffer. We do this by resizing the the window. This orphans the GLXPixmap (and texture) that the browser uses to display the front buffer.

BUG=None
TEST=None


Committed: http://src.chromium.org/viewvc/chrome?view=rev&revision=110540

[jonathan.backer, 2011-11-17 14:01:53]

This needs a bit more testing. I tested it on a TOUCHUI build running on an
intel graphics laptop. I saw an noticable improvement by looking at
/sys/kernel/debug/dri/0/i915_gem_objects when opening multiple accelerated tabs.

Unfortunately, stumpy was grumpy (renderers are crashing on ASSERTION FAILED:
!m_textures.get(token).isProtected with multiple accelerated tabs).

[piman, 2011-11-17 15:49:33]

http://codereview.chromium.org/8585030/diff/1/content/common/gpu/image_transp...
File content/common/gpu/image_transport_surface_linux.cc (right):

http://codereview.chromium.org/8585030/diff/1/content/common/gpu/image_transp...
content/common/gpu/image_transport_surface_linux.cc:469: needs_resize_ = true;
Wouldn't you want to set needs_resize_ in the other case instead?

[jonathan.backer, 2011-11-17 15:56:09]

http://codereview.chromium.org/8585030/diff/1/content/common/gpu/image_transp...
File content/common/gpu/image_transport_surface_linux.cc (right):

http://codereview.chromium.org/8585030/diff/1/content/common/gpu/image_transp...
content/common/gpu/image_transport_surface_linux.cc:469: needs_resize_ = true;
On 2011/11/17 15:49:34, piman wrote:
> Wouldn't you want to set needs_resize_ in the other case instead?

Done.

[piman, 2011-11-17 15:57:55]

LGTM. I suspect your WebKit assert is unrelated, but who knows...

[commit-bot: I haz the power, 2011-11-17 18:02:16]

CQ is trying da patch. Follow status at
https://chromium-status.appspot.com/cq/backer@chromium.org/8585030/2002

[commit-bot: I haz the power, 2011-11-17 20:05:37]

Change committed as 110540