Animations: Add the effect clipping primitive to web animations

Animations: Add the effect clipping primitive to web animations

This change adds the effect clipping primitives startClip and endClip
to the web animations API, behind the experimental web platform features
flag. The start clip is relative to the start time while end clip is
relative to the end time, synonymous to delay. These clip primitives
prevent an animation from applying outside of these values.

These clip primitives allows groups to be implemented on top of web
animations, as well as enable some work in DevTools.

BUG=495444
Committed: https://src.chromium.org/viewvc/blink?view=rev&revision=196739

[samli, 2015-06-03 05:45:35]

samli@chromium.org changed reviewers:
+ dstockwell@chromium.org

[samli, 2015-06-03 05:45:35]

PTAL.

[dstockwell, 2015-06-04 01:32:06]

https://codereview.chromium.org/1162253005/diff/1/Source/core/animation/Anima...
File Source/core/animation/Animation.cpp (right):

https://codereview.chromium.org/1162253005/diff/1/Source/core/animation/Anima...
Source/core/animation/Animation.cpp:800: if (!isNull(inheritedTime) &&
clipped(m_held && (!limited(inheritedTime) || isNull(m_startTime)) ?
inheritedTime : calculateCurrentTime()))
This might be better:

if (!isNull(inheritedTime)) {
  double timeForClipping = m_held && (!limited(inheritedTime) ||
isNull(m_startTime))
      // comment
      ? inheritedTime
      // other comment
      : calculateCurrentTime();
  if (clipped(timeForClipping))
    inheritedTime = nullValue();
}

https://codereview.chromium.org/1162253005/diff/1/Source/core/animation/Anima...
Source/core/animation/Animation.cpp:804: inheritedTime = -1;
this probably breaks clipping when clipStart is between -1 and 0

https://codereview.chromium.org/1162253005/diff/1/Source/core/animation/Anima...
Source/core/animation/Animation.cpp:853: double
Animation::clipTimeToEffectChange(double result)
const?

https://codereview.chromium.org/1162253005/diff/1/Source/core/animation/Anima...
Source/core/animation/Animation.cpp:860: result = std::min(result, (m_endClip +
sourceEnd() - currentTime) / m_playbackRate);
This might prevent firing the finish event.

[samli, 2015-06-09 01:23:54]

https://codereview.chromium.org/1162253005/diff/1/Source/core/animation/Anima...
File Source/core/animation/Animation.cpp (right):

https://codereview.chromium.org/1162253005/diff/1/Source/core/animation/Anima...
Source/core/animation/Animation.cpp:800: if (!isNull(inheritedTime) &&
clipped(m_held && (!limited(inheritedTime) || isNull(m_startTime)) ?
inheritedTime : calculateCurrentTime()))
On 2015/06/04 at 01:32:06, dstockwell wrote:
> This might be better:
> 
> if (!isNull(inheritedTime)) {
>   double timeForClipping = m_held && (!limited(inheritedTime) ||
isNull(m_startTime))
>       // comment
>       ? inheritedTime
>       // other comment
>       : calculateCurrentTime();
>   if (clipped(timeForClipping))
>     inheritedTime = nullValue();
> }

Done.

https://codereview.chromium.org/1162253005/diff/1/Source/core/animation/Anima...
Source/core/animation/Animation.cpp:804: inheritedTime = -1;
On 2015/06/04 at 01:32:06, dstockwell wrote:
> this probably breaks clipping when clipStart is between -1 and 0

Yay, this isn't a problem.

https://codereview.chromium.org/1162253005/diff/1/Source/core/animation/Anima...
Source/core/animation/Animation.cpp:853: double
Animation::clipTimeToEffectChange(double result)
On 2015/06/04 at 01:32:06, dstockwell wrote:
> const?

Done.

https://codereview.chromium.org/1162253005/diff/1/Source/core/animation/Anima...
Source/core/animation/Animation.cpp:860: result = std::min(result, (m_endClip +
sourceEnd() - currentTime) / m_playbackRate);
On 2015/06/04 at 01:32:06, dstockwell wrote:
> This might prevent firing the finish event.

It shouldn't. This function always returns as smaller time than before since no
optimisations are made.

[dstockwell, 2015-06-09 01:28:06]

lgtm

[samli, 2015-06-09 01:31:16]

The CQ bit was checked by samli@chromium.org

[commit-bot: I haz the power, 2015-06-09 01:32:19]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1162253005/20001

[commit-bot: I haz the power, 2015-06-09 04:23:46]

The CQ bit was unchecked by commit-bot@chromium.org

[commit-bot: I haz the power, 2015-06-09 04:23:47]

Try jobs failed on following builders:
  win_blink_rel on tryserver.blink (JOB_FAILED,
http://build.chromium.org/p/tryserver.blink/builders/win_blink_rel/builds/65773)

[samli, 2015-06-09 04:41:24]

The CQ bit was checked by samli@chromium.org

[commit-bot: I haz the power, 2015-06-09 04:41:31]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1162253005/20001

[commit-bot: I haz the power, 2015-06-09 05:47:39]

Committed patchset #2 (id:20001) as
https://src.chromium.org/viewvc/blink?view=rev&revision=196739