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

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

Index: third_party/WebKit/LayoutTests/media/controls/overlay-play-button.js
diff --git a/third_party/WebKit/LayoutTests/media/controls/overlay-play-button.js b/third_party/WebKit/LayoutTests/media/controls/overlay-play-button.js
new file mode 100644
index 0000000000000000000000000000000000000000..5feccd59848fc0872e2b372166d0dee05ac7b143
--- /dev/null
+++ b/third_party/WebKit/LayoutTests/media/controls/overlay-play-button.js
@@ -0,0 +1,38 @@
+// Defined in core/html/shadow/MediaControls.cpp.
+// Minimum width is 48px.
+var NARROW_VIDEO_WIDTH = 40;
+var NORMAL_VIDEO_WIDTH = 200;
+// Minimum height is 116px.
+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;
+  });
+}