Media Controls: enable feature to use cut-out whenever possible.

It's Android only. Trunk currently allows the user to expand into the
cutout area. With this change, it will instead allow the user to reduce
out of the cutout area.

Bug: 1077400
Change-Id: I99c15f671c0b085dcaf770e594cd06e722192a9b
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2218453
Commit-Queue: Mounir Lamouri <mlamouri@chromium.org>
Auto-Submit: Mounir Lamouri <mlamouri@chromium.org>
Reviewed-by: David Bokan <bokan@chromium.org>
Cr-Commit-Position: refs/heads/master@{#772426}

third_party/blink/renderer/modules/media_controls/media_controls_display_cutout_delegate_test.cc

@@ -289,7 +289,11 @@ TEST_F(MediaControlsDisplayCutoutDelegateTest, SingleTouchGesture_Noop) {
   // Simulate a single touch gesture and make sure it had no effect.
   SimulateEnterFullscreen();
   SimulateSingleTouchGesture();
-  EXPECT_EQ(mojom::ViewportFit::kAuto, CurrentViewportFit());
+  mojom::ViewportFit expected =
+      RuntimeEnabledFeatures::MediaControlsUseCutOutByDefaultEnabled()
+          ? mojom::ViewportFit::kCoverForcedByUserAgent
+          : mojom::ViewportFit::kAuto;
+  EXPECT_EQ(expected, CurrentViewportFit());
 }
 
 TEST_F(MediaControlsDisplayCutoutDelegateTest, TouchCancelShouldClearState) {
@@ -304,7 +308,11 @@ TEST_F(MediaControlsDisplayCutoutDelegateTest, TouchCancelShouldClearState) {
   list = CreateTouchListWithTwoPoints(1, 1, -1, -1);
   SimulateEvent(CreateTouchEventWithList(event_type_names::kTouchcancel, list));
   EXPECT_FALSE(HasGestureState());
-  EXPECT_EQ(mojom::ViewportFit::kAuto, CurrentViewportFit());
+  mojom::ViewportFit expected =
+      RuntimeEnabledFeatures::MediaControlsUseCutOutByDefaultEnabled()
+          ? mojom::ViewportFit::kCoverForcedByUserAgent
+          : mojom::ViewportFit::kAuto;
+  EXPECT_EQ(expected, CurrentViewportFit());
 }
 
 TEST_F(MediaControlsDisplayCutoutDelegateTest, TouchEndShouldClearState) {
@@ -319,7 +327,12 @@ TEST_F(MediaControlsDisplayCutoutDelegateTest, TouchEndShouldClearState) {
   list = CreateTouchListWithTwoPoints(1, 1, -1, -1);
   SimulateEvent(CreateTouchEventWithList(event_type_names::kTouchend, list));
   EXPECT_FALSE(HasGestureState());
-  EXPECT_EQ(mojom::ViewportFit::kAuto, CurrentViewportFit());
+
+  mojom::ViewportFit expected =
+      RuntimeEnabledFeatures::MediaControlsUseCutOutByDefaultEnabled()
+          ? mojom::ViewportFit::kCoverForcedByUserAgent
+          : mojom::ViewportFit::kAuto;
+  EXPECT_EQ(expected, CurrentViewportFit());
 }
 
 TEST_F(MediaControlsDisplayCutoutDelegateTest, DefaultExpand) {

third_party/blink/renderer/platform/runtime_enabled_features.json5

@@ -1049,7 +1049,8 @@
       status: {"Android": "stable"},
     },
     {
-      name: "MediaControlsUseCutOutByDefault"
+      name: "MediaControlsUseCutOutByDefault",
+      status: "stable",
     },
     {
       name: "MediaDocumentDownloadButton",