Remove unreferenced media player PNGs.

Remove unreferenced media player PNGs.

Remove _down and _hover variants of most media controls UI PNGs that are included in the resource bundles but not referenced anywhere i can find.  cat ... |wc -c shows about 140KB.

ChromePublic.apk shrinks by 138KB.

BUG=543173
Committed: https://crrev.com/72de1e4c785f688ca7680fe3d3b0c1da9d44aa8a
Cr-Commit-Position: refs/heads/master@{#355078}

[liberato (no reviews please), 2015-10-14 18:22:10]

liberato@chromium.org changed reviewers:
+ jochen@chromium.org, philipj@opera.com

[philipj_slow, 2015-10-16 12:09:39]

LGTM

I'm pretty sure these are safe to remove, but to make sure, can you check how
they were used when they were added, and assuming that they were used at all,
when they became unused? I like reading commit messages with a bit of archeology
notes in them :)

[liberato (no reviews please), 2015-10-16 19:37:16]

On 2015/10/16 12:09:39, philipj wrote:
> LGTM
> 
> I'm pretty sure these are safe to remove, but to make sure, can you check how
> they were used when they were added, and assuming that they were used at all,
> when they became unused? I like reading commit messages with a bit of
archeology
> notes in them :)

i've been unable to find any reference to them outside of the grd files,
blink_resource_constants.h, and blink_platform_impl.cc .  from controls/paint,
"git rev-list 2960437b08237ef8d0dbb779394d44116adb3b4e . |xargs git grep
mediaplayer |grep Hover" shows no results.  the sha-1 is one on the pre-blink
roll tree, just to avoid walking into chrome proper.

i've got a 'git rev-list' running in WebKit/Source, though that seems to take
forever.... wait, just finished.  found nothing.

-fl

[liberato (no reviews please), 2015-10-16 19:37:22]

The CQ bit was checked by liberato@chromium.org

[commit-bot: I haz the power, 2015-10-16 19:37:52]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1394963004/1
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1394963004/1

[commit-bot: I haz the power, 2015-10-16 19:46:30]

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

[commit-bot: I haz the power, 2015-10-16 19:46:31]

Try jobs failed on following builders:
  chromium_presubmit on tryserver.chromium.linux (JOB_FAILED,
http://build.chromium.org/p/tryserver.chromium.linux/builders/chromium_presub...)

[philipj_slow, 2015-10-19 07:39:31]

On 2015/10/16 19:37:16, liberato wrote:
> On 2015/10/16 12:09:39, philipj wrote:
> > LGTM
> > 
> > I'm pretty sure these are safe to remove, but to make sure, can you check
how
> > they were used when they were added, and assuming that they were used at
all,
> > when they became unused? I like reading commit messages with a bit of
> archeology
> > notes in them :)
> 
> i've been unable to find any reference to them outside of the grd files,
> blink_resource_constants.h, and blink_platform_impl.cc .  from controls/paint,
> "git rev-list 2960437b08237ef8d0dbb779394d44116adb3b4e . |xargs git grep
> mediaplayer |grep Hover" shows no results.  the sha-1 is one on the pre-blink
> roll tree, just to avoid walking into chrome proper.
> 
> i've got a 'git rev-list' running in WebKit/Source, though that seems to take
> forever.... wait, just finished.  found nothing.
> 
> -fl

These were added in 2011:
https://codereview.chromium.org/7278037

The tracking bug for all of that was:
https://code.google.com/p/chromium/issues/detail?id=88489

Looking at the tree after the last <http://trac.webkit.org/changeset/128075> of
those changes, it looks like the resources are used in
Source/WebCore/rendering/RenderMediaControlsChromium.cpp but there's no use of
the hover stuff AFAICT.

In other words, still LGTM. I was expecting to find that back then there was a
system that automatically constructed the names for these extra resources, so
they wouldn't show up in a grep, but it seems it was not so. The code to use
them was simply never written.

[jochen (gone - plz use gerrit), 2015-10-20 09:38:24]

lgtm

[liberato (no reviews please), 2015-10-20 15:05:38]

The CQ bit was checked by liberato@chromium.org

[commit-bot: I haz the power, 2015-10-20 15:06:07]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1394963004/1
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1394963004/1

[commit-bot: I haz the power, 2015-10-20 16:41:39]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2015-10-20 16:42:18]

Patchset 1 (id:??) landed as
https://crrev.com/72de1e4c785f688ca7680fe3d3b0c1da9d44aa8a
Cr-Commit-Position: refs/heads/master@{#355078}