aura: apply brightness filter last to improve perf

aura: apply brightness filter last to improve perf

https://bugs.webkit.org/show_bug.cgi?id=92059 adds an optimization on color
matrix filters so that they can be combined in a single pass as long as the
resulting colors don't need to be clamped. Brightness needs clamping, so it
should go last.

This also fixes an uninitialized value that made us stick a grayscale filter randomly on layers.

BUG=138645
TEST=new startup animation


Committed: http://src.chromium.org/viewvc/chrome?view=rev&revision=148837

[Mr4D (OOO till 08-26), 2012-07-26 13:57:00]

lgtm

https://chromiumcodereview.appspot.com/10833027/diff/2001/ui/compositor/layer.cc
File ui/compositor/layer.cc (right):

https://chromiumcodereview.appspot.com/10833027/diff/2001/ui/compositor/layer...
ui/compositor/layer.cc:304: }
Good old times... I remember when I did this kind of changes. I suppose you are
combining shader code there? Hmmmm. really want to look into that again :)

[commit-bot: I haz the power, 2012-07-26 17:06:18]

CQ is trying da patch. Follow status at
https://chromium-status.appspot.com/cq/piman@chromium.org/10833027/2001

[commit-bot: I haz the power, 2012-07-26 18:28:24]

Try job failure for 10833027-2001 (retry) on linux_clang for step "compile"
(clobber build).
It's a second try, previously, step "compile" failed.
http://build.chromium.org/p/tryserver.chromium/buildstatus?builder=linux_clan...

[commit-bot: I haz the power, 2012-07-26 19:31:20]

CQ is trying da patch. Follow status at
https://chromium-status.appspot.com/cq/piman@chromium.org/10833027/2001

[commit-bot: I haz the power, 2012-07-26 23:45:07]

Try job failure for 10833027-2001 (retry) on linux_rel for step "browser_tests".
It's a second try, previously, steps "interactive_ui_tests, browser_tests"
failed.
http://build.chromium.org/p/tryserver.chromium/buildstatus?builder=linux_rel&...

[commit-bot: I haz the power, 2012-07-26 23:57:00]

CQ is trying da patch. Follow status at
https://chromium-status.appspot.com/cq/piman@chromium.org/10833027/2001

[commit-bot: I haz the power, 2012-07-27 03:03:51]

Try job failure for 10833027-2001 (retry) on win_rel for step "browser_tests".
It's a second try, previously, step "browser_tests" failed.
http://build.chromium.org/p/tryserver.chromium/buildstatus?builder=win_rel&nu...

[commit-bot: I haz the power, 2012-07-27 03:26:34]

CQ is trying da patch. Follow status at
https://chromium-status.appspot.com/cq/piman@chromium.org/10833027/2001

[commit-bot: I haz the power, 2012-07-27 03:54:19]

Try job failure for 10833027-2001 (retry) on linux_clang for step "compile"
(clobber build).
It's a second try, previously, step "compile" failed.
http://build.chromium.org/p/tryserver.chromium/buildstatus?builder=linux_clan...

[commit-bot: I haz the power, 2012-07-27 21:17:36]

CQ is trying da patch. Follow status at
https://chromium-status.appspot.com/cq/piman@chromium.org/10833027/3007

[commit-bot: I haz the power, 2012-07-27 22:42:47]

Change committed as 148837

[Nikita (slow), 2012-07-28 01:49:54]

https://chromiumcodereview.appspot.com/10833027/diff/2001/ui/compositor/layer.cc
File ui/compositor/layer.cc (right):

https://chromiumcodereview.appspot.com/10833027/diff/2001/ui/compositor/layer...
ui/compositor/layer.cc:81: layer_grayscale_(0.0f),
Oh, sorry for this one.