New media playback UI.

Source/core/frame/Settings.in

Index: Source/core/frame/Settings.in
diff --git a/Source/core/frame/Settings.in b/Source/core/frame/Settings.in
index 08bbb47efa225b294d03f0ccb52db6c1ae11e4ba..45ecaf163171d8c88c0c875be75126f208f632a3 100644
--- a/Source/core/frame/Settings.in
+++ b/Source/core/frame/Settings.in
@@ -351,3 +351,19 @@ textTrackTextSize type=String
 lowPriorityIframes initial=false
 
 reportWheelOverscroll initial=false
+
+# Do we want to try to save screen real estate in the media player by hiding
+# the volume slider?  It is not guaranteed that the volume slider will always
+# be hidden if this is set.
+preferHiddenVolumeSlider initial=false

[philipj_slow, 2015/07/10 14:51:58]

Could these be collapsed into a single setting, after all I suppose they will
always be in sync.

[liberato (no reviews please), 2015/07/10 15:32:19]

i did that originally, but separated them for reasons that are no longer clear
to me after a few hours sleep.

i'll merge.

+
+# Do we want to try to save screen real estate in the media player by hiding
+# the mute button when possible?
+preferHiddenMuteButton initial=false
+
+# The media player will only hide volume / mute if the corresponding
+# prefer* setting is on, and if it's using the new UI.  This setting lets
+# us override the second part, and enable it for the previous UI as well.
+# TODO(liberato): remove this setting once the old UI is removed.  It
+# facilitates testing without worrying about which UI is enabled.
+forceAllowHiddenAudioElements initial=false

[philipj_slow, 2015/07/10 14:21:35]

Setting that are for testing only can be put in
Source/core/testing/InternalSettings.*

testing/Internals.idl is also an option, you could use that to reach into
MediaPlayer and tickle it directly, but it doesn't matter which way it's done I
think.

[liberato (no reviews please), 2015/07/10 15:32:19]

that's cool!  I moved it to Internals.idl, since that's ten shades of awesome.