New InvalidationReasons: InvalidationBecameVisible and InvalidationBecameInvisible

New InvalidationReasons: InvalidationBecameVisible and InvalidationBecameInvisible

The reasons will be displayed in tracing.
We can also pass more specific invalidation reasons via
WebInvalidationDebugAnnotations in the future.

BUG=410465
Committed: https://src.chromium.org/viewvc/blink?view=rev&revision=182453

[Xianzhu, 2014-09-22 20:17:57]

wangxianzhu@chromium.org changed reviewers:
+ dsinclair@chromium.org, jchaffraix@chromium.org, kouhei@chromium.org,
leviw@chromium.org

[dsinclair, 2014-09-22 20:21:35]

How come we issue less invalidations on the failing test? Is it because we moved
the check later in the chain?

Is there a current use for this, or is it just to see if it's useful for
tracking first paint?

[Xianzhu, 2014-09-22 20:41:10]

On 2014/09/22 20:21:35, dsinclair wrote:
> How come we issue less invalidations on the failing test? Is it because we
moved
> the check later in the chain?
> 

Yes, it's because of the move which avoids unnecessary invalidation for empty
containers.

> Is there a current use for this, or is it just to see if it's useful for
> tracking first paint?

One use could be about more specific invalidation reasons in tracing.

About, first paint tracking is great, but it has some issues:
- It doesn't necessarily mean DOM change. Reattachment of RenderObjects also
causes "first paints".
- It doesn't actually track the first paint of RenderObjects, but the first
paint of the paintInvalidationContainer.
As we can't accurately track actual first paints (of DOM nodes), I think we
could use simpler method which might be a little worse than the current first
paint tracking, but the code and the meaning are clearer.

[dsinclair, 2014-09-22 20:46:36]

lgtm with nit.

https://codereview.chromium.org/577353005/diff/1/Source/core/rendering/Render...
File Source/core/rendering/RenderObject.cpp (right):

https://codereview.chromium.org/577353005/diff/1/Source/core/rendering/Render...
Source/core/rendering/RenderObject.cpp:1262: return "become visible";
nit: became

[Xianzhu, 2014-09-22 21:45:56]

https://codereview.chromium.org/577353005/diff/1/Source/core/rendering/Render...
File Source/core/rendering/RenderObject.cpp (right):

https://codereview.chromium.org/577353005/diff/1/Source/core/rendering/Render...
Source/core/rendering/RenderObject.cpp:1262: return "become visible";
On 2014/09/22 20:46:36, dsinclair wrote:
> nit: became

Done.

[Xianzhu, 2014-09-22 21:47:29]

Created another CL for alternative way of tracking first paints
(https://codereview.chromium.org/593873002).

The new invalidation reasons added by this CL won't be for tracking first
paints.

[leviw_travelin_and_unemployed, 2014-09-22 22:10:15]

lgtm

[Xianzhu, 2014-09-22 22:48:25]

The CQ bit was checked by wangxianzhu@chromium.org

[commit-bot: I haz the power, 2014-09-22 22:49:25]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/577353005/20001

[commit-bot: I haz the power, 2014-09-22 22:55:16]

Committed patchset #2 (id:20001) as 182453