views: Access the Canvas through recorders not through PaintContext.

views: Access the Canvas through recorders not through PaintContext.

The PaintContext may be backed by a DisplayItemList in the future so it
will not have a canvas(). Instead invoke a PaintRecorder to use a canvas
or another Recorder to do other operations such as clip or opacity.

This adds a CompositingRecorder for compositing operations like opacity.
It could also support effects like blend modes, and will generate
cc::CompositingDisplayItems in the future.

R=sky
BUG=466426
Committed: https://crrev.com/38125cee3b20bcad023fcf96786951d36c091727
Cr-Commit-Position: refs/heads/master@{#323981}

[danakj, 2015-04-06 19:00:44]

danakj@chromium.org changed reviewers:
+ piman@chromium.org

[Peter Kasting, 2015-04-06 19:24:35]

pkasting@chromium.org changed reviewers:
+ pkasting@chromium.org

[Peter Kasting, 2015-04-06 19:24:36]

c/b/ui/views LGTM assuming there's a good reason for my question below.

https://codereview.chromium.org/1054783003/diff/1/chrome/browser/ui/views/boo...
File chrome/browser/ui/views/bookmarks/bookmark_bar_view.cc (right):

https://codereview.chromium.org/1054783003/diff/1/chrome/browser/ui/views/boo...
chrome/browser/ui/views/bookmarks/bookmark_bar_view.cc:1016: 
Nit: Blank line not necessary

https://codereview.chromium.org/1054783003/diff/1/chrome/browser/ui/views/omn...
File chrome/browser/ui/views/omnibox/omnibox_popup_contents_view.cc (right):

https://codereview.chromium.org/1054783003/diff/1/chrome/browser/ui/views/omn...
chrome/browser/ui/views/omnibox/omnibox_popup_contents_view.cc:428:
ui::PaintRecorder recorder(context);
How come this needs to be scoped?  It makes it look as if we'll reset the canvas
draw color back to what it was before at the end of the scope.  I assume reality
is different somehow?

[danakj, 2015-04-06 19:29:07]

https://codereview.chromium.org/1054783003/diff/1/chrome/browser/ui/views/omn...
File chrome/browser/ui/views/omnibox/omnibox_popup_contents_view.cc (right):

https://codereview.chromium.org/1054783003/diff/1/chrome/browser/ui/views/omn...
chrome/browser/ui/views/omnibox/omnibox_popup_contents_view.cc:428:
ui::PaintRecorder recorder(context);
On 2015/04/06 19:24:36, Peter Kasting wrote:
> How come this needs to be scoped?  It makes it look as if we'll reset the
canvas
> draw color back to what it was before at the end of the scope.  I assume
reality
> is different somehow?

Right, PaintRecorder doesn't SaveRestore like the clip/transform one.

This is scoped because Painting can not be nested. The things inside this scope
are going to end up in a single DrawingDisplayItem in the DisplayItemList.

[danakj, 2015-04-06 19:29:59]

https://codereview.chromium.org/1054783003/diff/1/chrome/browser/ui/views/boo...
File chrome/browser/ui/views/bookmarks/bookmark_bar_view.cc (right):

https://codereview.chromium.org/1054783003/diff/1/chrome/browser/ui/views/boo...
chrome/browser/ui/views/bookmarks/bookmark_bar_view.cc:1016: 
On 2015/04/06 19:24:36, Peter Kasting wrote:
> Nit: Blank line not necessary

Done.

[piman, 2015-04-06 20:16:38]

lgtm

[danakj, 2015-04-06 23:03:12]

The CQ bit was checked by danakj@chromium.org

[danakj, 2015-04-06 23:03:12]

The patchset sent to the CQ was uploaded after l-g-t-m from
pkasting@chromium.org, piman@chromium.org
Link to the patchset: https://codereview.chromium.org/1054783003/#ps30001
(title: "uiviews-recorder: .")

[commit-bot: I haz the power, 2015-04-06 23:03:32]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1054783003/30001

[commit-bot: I haz the power, 2015-04-07 00:00:14]

Committed patchset #3 (id:30001)

[commit-bot: I haz the power, 2015-04-07 00:01:37]

Patchset 3 (id:??) landed as
https://crrev.com/38125cee3b20bcad023fcf96786951d36c091727
Cr-Commit-Position: refs/heads/master@{#323981}