Support text track selection in video controls

Source/core/css/mediaControls.css

Index: Source/core/css/mediaControls.css
diff --git a/Source/core/css/mediaControls.css b/Source/core/css/mediaControls.css
index 794af3fa6e30c5c7578995075b513551f5f14ed9..104d8b9ff7079e87f8e06db115e4ae694c5b0f6e 100644
--- a/Source/core/css/mediaControls.css
+++ b/Source/core/css/mediaControls.css
@@ -331,6 +331,79 @@ video::-webkit-media-controls-toggle-closed-captions-button {
     color: inherit;
 }
 
+video::-webkit-scrollbar {
+    width: 12px;
+}
+
+video::-webkit-scrollbar-track {
+    box-shadow: inset 0 0 6px rgba(20, 20, 20, 0.3);
+    border-radius: 10px;
+}
+
+video::-webkit-scrollbar-thumb {
+    border-radius: 10px;
+    background-color: rgba(80, 80, 80, 0.8);
+    box-shadow: inset 0 0 6px rgba(20, 20, 20, 0.5);
+}
+
+video::-internal-media-controls-text-track-list {
+    position: absolute;
+    bottom: 35px;

[philipj_slow, 2015/05/05 14:36:56]

You will need to also tweak mediaControlsAndroid.css so that any numbers like
this are correct for the larger size of the controls on Android.

[srivats, 2016/02/23 01:39:26]

Will do.

+    right: 5px;
+    background: rgba(20, 20, 20, 0.8);

[philipj_slow, 2015/05/05 14:36:56]

Does background:inherit work, given that the parent is the
-webkit-media-controls-panel?

[srivats, 2016/02/23 01:39:26]

The parent is now the enclosure so background:inherit won't work.

+    max-width: 50%;
+    max-height: 250px;

[philipj_slow, 2015/05/05 14:36:56]

This means that the list can be bigger than the video and that is in fact what
happens. Oddly enough, it seems like overflow:hidden on the video element has no
effect. Why is that?

[fs, 2015/05/05 15:32:44]

Probably because the video element uses LayoutReplaced (which doesn't handle
overflow - because it [usually] never overflows IIUC)

[philipj_slow, 2015/05/06 09:28:43]

Oh right. I tried display:block too but in hindsight that couldn't make the
video anything other than LayoutReplaced because if it's not a LayoutMedia the
controls wouldn't even be visible. Anyway, I think it's just fine that
overflow:hidden doesn't work, just wanted to understand why.

+    border-radius: 5px;
+    overflow-x: hidden;
+    overflow-y: auto;
+    text-overflow: ellipsis;
+    margin-bottom: 5px;
+    font-family: Arial, Helvetica, sans-serif;

[philipj_slow, 2015/05/05 14:36:56]

Since font-family is inherited, can this be moved to
audio::-webkit-media-controls, video::-webkit-media-controls { ... }?

[srivats, 2016/02/23 01:39:26]

Done.

+    white-space: nowrap;
+    display: block;

[philipj_slow, 2015/05/05 14:36:56]

Is display:block needed given that this is already a div element?

[srivats, 2016/02/23 01:39:26]

Removed

+    padding: 10px;
+    font-weight: bold;
+    font-size: 16px;

[philipj_slow, 2015/05/05 14:36:56]

I found it a bit jarring that the font size is so much bigger than the the time
display in the controls.

[srivats, 2016/02/23 01:39:26]

Made it the same as the font-size of time display.

+}
+
+video::-internal-media-controls-text-track-list-header {
+    margin: 0;
+    text-shadow: 0 1px 0 black;
+    text-align: center;
+    color: gray;

[philipj_slow, 2015/05/05 14:36:56]

I found this rather low contrast, probably not readable enough for all people.

[srivats, 2016/02/23 01:39:26]

Changed it here and in the new material design UI.

+    padding: 4px 0 4px 4px;
+    border-bottom: 1px solid #555;
+}
+
+video::-internal-media-controls-text-track-list-item {
+    display: block;
+    color: white;
+    padding: 4px 30px 4px 10px;
+    border-bottom: 1px solid #555;
+    text-align: start;
+    line-height: 25px;
+}
+
+video::-internal-media-controls-text-track-list-item:hover {
+    background-color: rgba(105, 105, 105, 0.8);
+}
+
+video::-internal-media-controls-text-track-list-item-input {
+    -webkit-appearance: media-track-selection-checkmark;
+    position: relative;
+    visibility: hidden;
+    top: -2px;

[philipj_slow, 2015/05/05 14:36:56]

What's this for? Is the image element misaligned (vertical-align:middle not
working) or is this compensating for the PNG itself not having the checkmark
where it should?

[srivats, 2016/02/23 01:39:26]

It looks misaligned without the -2px. Might be an issue with the PNG but I tried
using a different one and it still looked off.

[philipj_slow, 2016/03/01 11:21:04]

Following up in other CL.

+    left: 0;
+    vertical-align: middle;
+    margin: 0 5px 0 0;
+    width: 25px;
+    height: 25px;
+}
+
+video::-internal-media-controls-text-track-list-item-input:checked {
+    visibility: visible;
+}
+
 audio::-webkit-media-controls-fullscreen-volume-slider, video::-webkit-media-controls-fullscreen-volume-slider {
     display: none;
 }