Revert "Add `embedderId` to `PointerEvent` (#60930)" (#61010)

This reverts commit 2ab509943660c62281e7b48648c06b057e028c65.
diff --git a/bin/internal/engine.version b/bin/internal/engine.version
index c2a2f7b..2184e18 100644
--- a/bin/internal/engine.version
+++ b/bin/internal/engine.version
@@ -1 +1 @@
-d0d6a4c2362d2ed478006bb3b01c34c0e96033b4
+f22ac9da9c78215a3caf038b2205444dc2ee3d0d
diff --git a/dev/integration_tests/android_views/lib/wm_integrations.dart b/dev/integration_tests/android_views/lib/wm_integrations.dart
index 9112353..b12c5a9 100644
--- a/dev/integration_tests/android_views/lib/wm_integrations.dart
+++ b/dev/integration_tests/android_views/lib/wm_integrations.dart
@@ -219,7 +219,6 @@
       eventTime: 723657071,
       action: 0,
       xPrecision: 1.0,
-      motionEventId: 1,
     ),
     AndroidMotionEvent(
       downTime: 723657071,
@@ -253,7 +252,6 @@
       edgeFlags: 0,
       source: 4098,
       flags: 0,
-      motionEventId: 2,
     ),
   ];
 }
diff --git a/packages/flutter/lib/src/gestures/converter.dart b/packages/flutter/lib/src/gestures/converter.dart
index 85eec8c..481e660 100644
--- a/packages/flutter/lib/src/gestures/converter.dart
+++ b/packages/flutter/lib/src/gestures/converter.dart
@@ -74,7 +74,6 @@
               radiusMax: radiusMax,
               orientation: datum.orientation,
               tilt: datum.tilt,
-              embedderId: datum.embedderId,
             );
             break;
           case ui.PointerChange.hover:
@@ -98,7 +97,6 @@
               orientation: datum.orientation,
               tilt: datum.tilt,
               synthesized: datum.synthesized,
-              embedderId: datum.embedderId,
             );
             break;
           case ui.PointerChange.down:
@@ -121,7 +119,6 @@
               radiusMax: radiusMax,
               orientation: datum.orientation,
               tilt: datum.tilt,
-              embedderId: datum.embedderId,
             );
             break;
           case ui.PointerChange.move:
@@ -147,7 +144,6 @@
               tilt: datum.tilt,
               platformData: datum.platformData,
               synthesized: datum.synthesized,
-              embedderId: datum.embedderId,
             );
             break;
           case ui.PointerChange.up:
@@ -171,7 +167,6 @@
               radiusMax: radiusMax,
               orientation: datum.orientation,
               tilt: datum.tilt,
-              embedderId: datum.embedderId,
             );
             break;
           case ui.PointerChange.cancel:
@@ -194,7 +189,6 @@
               radiusMax: radiusMax,
               orientation: datum.orientation,
               tilt: datum.tilt,
-              embedderId: datum.embedderId,
             );
             break;
           case ui.PointerChange.remove:
@@ -209,7 +203,6 @@
               distanceMax: datum.distanceMax,
               radiusMin: radiusMin,
               radiusMax: radiusMax,
-              embedderId: datum.embedderId,
             );
             break;
         }
@@ -224,7 +217,6 @@
               device: datum.device,
               position: position,
               scrollDelta: scrollDelta,
-              embedderId: datum.embedderId,
             );
             break;
           case ui.PointerSignalKind.none:
diff --git a/packages/flutter/lib/src/gestures/events.dart b/packages/flutter/lib/src/gestures/events.dart
index 9e041cc..055fabc 100644
--- a/packages/flutter/lib/src/gestures/events.dart
+++ b/packages/flutter/lib/src/gestures/events.dart
@@ -202,7 +202,6 @@
   /// Abstract const constructor. This constructor enables subclasses to provide
   /// const constructors so that they can be used in const expressions.
   const PointerEvent({
-    this.embedderId = 0,
     this.timeStamp = Duration.zero,
     this.pointer = 0,
     this.kind = PointerDeviceKind.touch,
@@ -233,14 +232,6 @@
   }) : localPosition = localPosition ?? position,
        localDelta = localDelta ?? delta;
 
-  /// Unique identifier that ties the [PointerEvent] to the embedder event that created it.
-  ///
-  /// No two pointer events can have the same [embedderId] on platforms that set it.
-  /// This is different from [pointer] identifier - used for hit-testing,
-  /// whereas [embedderId] is used to identify the platform event.
-  ///
-  /// On Android this is ID of the underlying [MotionEvent](https://developer.android.com/reference/android/view/MotionEvent).
-  final int embedderId;
 
   /// Time of event dispatch, relative to an arbitrary timeline.
   final Duration timeStamp;
@@ -513,7 +504,6 @@
     properties.add(IntProperty('platformData', platformData, defaultValue: 0, level: DiagnosticLevel.debug));
     properties.add(FlagProperty('obscured', value: obscured, ifTrue: 'obscured', level: DiagnosticLevel.debug));
     properties.add(FlagProperty('synthesized', value: synthesized, ifTrue: 'synthesized', level: DiagnosticLevel.debug));
-    properties.add(IntProperty('embedderId', embedderId, defaultValue: 0, level: DiagnosticLevel.debug));
   }
 
   /// Returns a complete textual description of this event.
@@ -602,7 +592,6 @@
     double tilt = 0.0,
     Matrix4 transform,
     PointerAddedEvent original,
-    int embedderId = 0,
   }) : super(
          timeStamp: timeStamp,
          kind: kind,
@@ -621,7 +610,6 @@
          tilt: tilt,
          transform: transform,
          original: original,
-         embedderId: embedderId,
        );
 
   @override
@@ -646,7 +634,6 @@
       tilt: tilt,
       transform: transform,
       original: original as PointerAddedEvent ?? this,
-      embedderId: embedderId,
     );
   }
 }
@@ -673,7 +660,6 @@
     double radiusMax = 0.0,
     Matrix4 transform,
     PointerRemovedEvent original,
-    int embedderId = 0,
   }) : super(
          timeStamp: timeStamp,
          kind: kind,
@@ -689,7 +675,6 @@
          radiusMax: radiusMax,
          transform: transform,
          original: original,
-         embedderId: embedderId,
        );
 
   @override
@@ -711,7 +696,6 @@
       radiusMax: radiusMax,
       transform: transform,
       original: original as PointerRemovedEvent ?? this,
-      embedderId: embedderId,
     );
   }
 }
@@ -754,7 +738,6 @@
     bool synthesized = false,
     Matrix4 transform,
     PointerHoverEvent original,
-    int embedderId = 0,
   }) : super(
          timeStamp: timeStamp,
          kind: kind,
@@ -781,7 +764,6 @@
          synthesized: synthesized,
          transform: transform,
          original: original,
-         embedderId: embedderId,
        );
 
   @override
@@ -819,7 +801,6 @@
       synthesized: synthesized,
       transform: transform,
       original: original as PointerHoverEvent ?? this,
-      embedderId: embedderId,
     );
   }
 }
@@ -863,7 +844,6 @@
     bool synthesized = false,
     Matrix4 transform,
     PointerEnterEvent original,
-    int embedderId = 0,
   }) : super(
          timeStamp: timeStamp,
          kind: kind,
@@ -890,7 +870,6 @@
          synthesized: synthesized,
          transform: transform,
          original: original,
-         embedderId: embedderId,
        );
 
   /// Creates an enter event from a [PointerHoverEvent].
@@ -968,7 +947,6 @@
       synthesized: synthesized,
       transform: transform,
       original: original as PointerEnterEvent ?? this,
-      embedderId: embedderId,
     );
   }
 }
@@ -1012,7 +990,6 @@
     bool synthesized = false,
     Matrix4 transform,
     PointerExitEvent original,
-    int embedderId = 0,
   }) : super(
          timeStamp: timeStamp,
          kind: kind,
@@ -1039,7 +1016,6 @@
          synthesized: synthesized,
          transform: transform,
          original: original,
-         embedderId: embedderId,
        );
 
   /// Creates an exit event from a [PointerHoverEvent].
@@ -1117,7 +1093,6 @@
       synthesized: synthesized,
       transform: transform,
       original: original as PointerExitEvent ?? this,
-      embedderId: embedderId,
     );
   }
 }
@@ -1149,7 +1124,6 @@
     double tilt = 0.0,
     Matrix4 transform,
     PointerDownEvent original,
-    int embedderId = 0,
   }) : super(
          timeStamp: timeStamp,
          pointer: pointer,
@@ -1174,7 +1148,6 @@
          tilt: tilt,
          transform: transform,
          original: original,
-         embedderId: embedderId,
        );
 
   @override
@@ -1204,7 +1177,6 @@
       tilt: tilt,
       transform: transform,
       original: original as PointerDownEvent ?? this,
-      embedderId: embedderId,
     );
   }
 }
@@ -1246,7 +1218,6 @@
     bool synthesized = false,
     Matrix4 transform,
     PointerMoveEvent original,
-    int embedderId = 0,
   }) : super(
          timeStamp: timeStamp,
          pointer: pointer,
@@ -1275,7 +1246,6 @@
          synthesized: synthesized,
          transform: transform,
          original: original,
-         embedderId: embedderId,
        );
 
   @override
@@ -1316,7 +1286,6 @@
       synthesized: synthesized,
       transform: transform,
       original: original as PointerMoveEvent ?? this,
-      embedderId: embedderId,
     );
   }
 }
@@ -1351,7 +1320,6 @@
     double tilt = 0.0,
     Matrix4 transform,
     PointerUpEvent original,
-    int embedderId = 0,
   }) : super(
          timeStamp: timeStamp,
          pointer: pointer,
@@ -1376,7 +1344,6 @@
          tilt: tilt,
          transform: transform,
          original: original,
-         embedderId: embedderId,
        );
 
   @override
@@ -1407,7 +1374,6 @@
       tilt: tilt,
       transform: transform,
       original: original as PointerUpEvent ?? this,
-      embedderId: embedderId,
     );
   }
 }
@@ -1429,7 +1395,6 @@
     Offset localPosition,
     Matrix4 transform,
     PointerSignalEvent original,
-    int embedderId = 0,
   }) : super(
          timeStamp: timeStamp,
          pointer: pointer,
@@ -1439,7 +1404,6 @@
          localPosition: localPosition,
          transform: transform,
          original: original,
-         embedderId: embedderId,
        );
 }
 
@@ -1460,7 +1424,6 @@
     this.scrollDelta = Offset.zero,
     Matrix4 transform,
     PointerScrollEvent original,
-    int embedderId = 0,
   }) : assert(timeStamp != null),
        assert(kind != null),
        assert(device != null),
@@ -1474,7 +1437,6 @@
          localPosition: localPosition,
          transform: transform,
          original: original,
-         embedderId: embedderId,
        );
 
   /// The amount to scroll, in logical pixels.
@@ -1494,7 +1456,6 @@
       scrollDelta: scrollDelta,
       transform: transform,
       original: original as PointerScrollEvent ?? this,
-      embedderId: embedderId,
     );
   }
 
@@ -1532,7 +1493,6 @@
     double tilt = 0.0,
     Matrix4 transform,
     PointerCancelEvent original,
-    int embedderId = 0,
   }) : super(
          timeStamp: timeStamp,
          pointer: pointer,
@@ -1557,7 +1517,6 @@
          tilt: tilt,
          transform: transform,
          original: original,
-         embedderId: embedderId,
        );
 
   @override
@@ -1587,7 +1546,6 @@
       tilt: tilt,
       transform: transform,
       original: original as PointerCancelEvent ?? this,
-      embedderId: embedderId,
     );
   }
 }
diff --git a/packages/flutter/lib/src/services/platform_views.dart b/packages/flutter/lib/src/services/platform_views.dart
index b3fe37b..97699cd 100644
--- a/packages/flutter/lib/src/services/platform_views.dart
+++ b/packages/flutter/lib/src/services/platform_views.dart
@@ -368,7 +368,6 @@
     @required this.edgeFlags,
     @required this.source,
     @required this.flags,
-    @required this.motionEventId,
   }) : assert(downTime != null),
        assert(eventTime != null),
        assert(action != null),
@@ -450,9 +449,6 @@
   /// See Android's [MotionEvent#getFlags](https://developer.android.com/reference/android/view/MotionEvent.html#getFlags()).
   final int flags;
 
-  /// Used to identify this [MotionEvent](https://developer.android.com/reference/android/view/MotionEvent.html) uniquely in the Flutter Engine.
-  final int motionEventId;
-
   List<dynamic> _asList(int viewId) {
     return <dynamic>[
       viewId,
@@ -470,7 +466,6 @@
       edgeFlags,
       source,
       flags,
-      motionEventId,
     ];
   }
 
@@ -607,7 +602,6 @@
       edgeFlags: 0,
       source: 0,
       flags: 0,
-      motionEventId: event.embedderId,
     );
   }