[webkit-reviews] review denied: [Bug 80899] [chromium] Make damage tracker accumulate damage until explicitly cleared : [Attachment 133359] Patch with updated unit tests

[bugzilla-daemon at webkit.org]

Adrienne Walker <enne at google.com> has denied Shawn Singh
<shawnsingh at chromium.org>'s request for review:
Bug 80899: [chromium] Make damage tracker accumulate damage until explicitly
cleared
https://bugs.webkit.org/show_bug.cgi?id=80899

Attachment 133359: Patch with updated unit tests
https://bugs.webkit.org/attachment.cgi?id=133359&action=review

------- Additional Comments from Adrienne Walker <enne at google.com>
View in context: https://bugs.webkit.org/attachment.cgi?id=133359&action=review


> Source/WebCore/ChangeLog:15
> +	   Before this patch, the damage tracker requires that every time the
> +	   backbuffer is drawn to, that change must be presented with
> +	   swapBuffers or postSubBuffer. This behavior is undesired; there
> +	   are reasons we don't want to present anything to the front buffer,
> +	   even though we may draw to the back buffer (for example, readback
> +	   for the thumbnailer.)

We call CCLTHI::swapBuffers() during readback for the thumbnailer, and thus
will clear the damage rect there.  Is that intended, given this comment?

> Source/WebKit/chromium/tests/CCDamageTrackerTest.cpp:242
> +    clearDamageForAllSurfaces(root.get());
>      child->setUpdateRect(FloatRect(10, 11, 12, 13));
>      emulateDrawingOneFrame(root.get());

Can you just wrap clearDamageForAllSurfaces into emulateDrawingOneFrame and
have some emulatePrepareOneFrameWithoutDrawing for the one corner case that you
don't need it?