Hide overlay play button if it can't be shown without clipping

third_party/WebKit/LayoutTests/virtual/android/media/controls/overlay-play-button.js

+// Defined in core/html/shadow/MediaControls.cpp.
+// Minimum width is 48px on both desktop and Android.

[mlamouri (slow - plz ping), 2017/03/08 19:13:04]

Isn't this actually define in css?

[steimel, 2017/03/09 16:42:24]

Well, the width (and height) of the play button is defined in
MediaControlsPainter.cpp. However, the max width (and max height) is defined in
MediaControls.cpp. It's just that the max width is the same as the width since
we're able to use the whole video width to display the button (unlike the
height).

+var NARROW_VIDEO_WIDTH = 40;
+var NORMAL_VIDEO_WIDTH = 200;
+// 116px for android, 100px for desktop.
+var NARROW_VIDEO_HEIGHT = 90;
+var NORMAL_VIDEO_HEIGHT = 200;
+
+function assertOverlayPlayButtonVisible(videoElement) {
+  assert_true(isVisible(overlayPlayButton(videoElement)),
+      "overlay play button should be visible");
+}
+
+function assertOverlayPlayButtonNotVisible(videoElement) {
+  assert_false(isVisible(overlayPlayButton(videoElement)),
+      "overlay play button should not be visible");
+}
+
+function overlayPlayButton(videoElement) {
+  var controlID = '-webkit-media-controls-overlay-play-button';
+  var button = mediaControlsElement(
+      window.internals.shadowRoot(videoElement).firstChild,
+      controlID);
+  if (!button)
+    throw 'Failed to find overlay play button';
+  return button;
+}
+
+function enableOverlayPlayButtonForTest(t) {
+  var mediaControlsOverlayPlayButtonValue =
+      internals.runtimeFlags.mediaControlsOverlayPlayButtonEnabled;
+  internals.runtimeFlags.mediaControlsOverlayPlayButtonEnabled = true;
+
+  t.add_cleanup(() => {
+    internals.runtimeFlags.mediaControlsOverlayPlayButtonEnabled =
+        mediaControlsOverlayPlayButtonValue;
+  });
+}