cc: Stop checking the result of GetInverse in OcclusionTracker.

cc: Stop checking the result of GetInverse in OcclusionTracker.

We don't draw layers with non-invertible transforms, so this check is
a waste. Especially in the case where we don't even use the inverse
transform.

R=enne

Committed: https://src.chromium.org/viewvc/chrome?view=rev&revision=291242

[enne (OOO), 2014-08-21 17:36:11]

lgtm

Offhand, this seems like a common pattern for cc to not care about inverses. 
Would it makes sense for gfx::Transform to have bool
GetInverseSafe(gfx::Transform*) that returns the result and void
GetInverse(gfx::Transform) that DCHECKs the result implicitly?

[danakj, 2014-08-21 17:38:53]

On 2014/08/21 17:36:11, enne wrote:
> lgtm
> 
> Offhand, this seems like a common pattern for cc to not care about inverses. 
> Would it makes sense for gfx::Transform to have bool
> GetInverseSafe(gfx::Transform*) that returns the result and void
> GetInverse(gfx::Transform) that DCHECKs the result implicitly?

Ya, we care about inverses only in a few places where we decide if we want to
draw the layer at all. I'm not sure about adding new APIs to Transform or not,
but ya I'll think about that.

[danakj, 2014-08-21 17:38:59]

The CQ bit was checked by danakj@chromium.org

[commit-bot: I haz the power, 2014-08-21 17:41:01]

CQ is trying da patch. Follow status at
 https://chromium-status.appspot.com/cq/danakj@chromium.org/492953002/1

[commit-bot: I haz the power, 2014-08-21 23:28:57]

Committed patchset #1 (1) as 291242