Fixed volume slider element event handling

Fixed volume slider element event handling

MediaControlVolumeSliderElement::defaultEventHandler has making
redundant calls to setVolume() & setMuted() on mouse activity. E.g. if
a mouse click changed the slider position, the above calls were made 4
times, once for each of these events: mousedown, input, mouseup,
DOMActive, click. This crack got exposed when PointerEvents are enabled
by default on M55, adding pointermove, pointerdown & pointerup to the
list.

This CL fixes the code to trigger the calls to setVolume() & setMuted()
only when the slider position is changed. Also added pointer events to
certain lists of mouse events in the code.

BUG=677900
Review-Url: https://codereview.chromium.org/2622273003
Cr-Commit-Position: refs/heads/master@{#446032}
(cherry picked from commit 74fce5949bdf05a92c2bc0bd98e6e3e977c55376)

Review-Url: https://codereview.chromium.org/2654183005 .
Cr-Commit-Position: refs/branch-heads/2987@{#106}
Cr-Branched-From: ad51088c0e8776e8dcd963dbe752c4035ba6dab6-refs/heads/master@{#444943}
Committed: https://chromium.googlesource.com/chromium/src/+/69bc0646f147fea740958753d085324cd6b5d2e4

[mustaq, 2017-01-26 16:54:17]

Description was changed from

==========
Fixed volume slider element event handling

MediaControlVolumeSliderElement::defaultEventHandler has making
redundant calls to setVolume() & setMuted() on mouse activity. E.g. if
a mouse click changed the slider position, the above calls were made 4
times, once for each of these events: mousedown, input, mouseup,
DOMActive, click. This crack got exposed when PointerEvents are enabled
by default on M55, adding pointermove, pointerdown & pointerup to the
list.

This CL fixes the code to trigger the calls to setVolume() & setMuted()
only when the slider position is changed. Also added pointer events to
certain lists of mouse events in the code.

BUG=677900

Review-Url: https://codereview.chromium.org/2622273003
Cr-Commit-Position: refs/heads/master@{#446032}
(cherry picked from commit 74fce5949bdf05a92c2bc0bd98e6e3e977c55376)
==========

to

==========
Fixed volume slider element event handling

MediaControlVolumeSliderElement::defaultEventHandler has making
redundant calls to setVolume() & setMuted() on mouse activity. E.g. if
a mouse click changed the slider position, the above calls were made 4
times, once for each of these events: mousedown, input, mouseup,
DOMActive, click. This crack got exposed when PointerEvents are enabled
by default on M55, adding pointermove, pointerdown & pointerup to the
list.

This CL fixes the code to trigger the calls to setVolume() & setMuted()
only when the slider position is changed. Also added pointer events to
certain lists of mouse events in the code.

BUG=677900

Review-Url: https://codereview.chromium.org/2622273003
Cr-Commit-Position: refs/heads/master@{#446032}
(cherry picked from commit 74fce5949bdf05a92c2bc0bd98e6e3e977c55376)

Review-Url: https://codereview.chromium.org/2654183005 .
Cr-Commit-Position: refs/branch-heads/2987@{#106}
Cr-Branched-From:
ad51088c0e8776e8dcd963dbe752c4035ba6dab6-refs/heads/master@{#444943}
Committed:
https://chromium.googlesource.com/chromium/src/+/69bc0646f147fea740958753d085...
==========

[mustaq, 2017-01-26 16:54:18]

Committed patchset #1 (id:1) manually as
69bc0646f147fea740958753d085324cd6b5d2e4.