Renamed the Driver API waitUntilFrameSync to waitUntilNoPendingFrame. (#36512)

diff --git a/packages/flutter_driver/lib/src/common/find.dart b/packages/flutter_driver/lib/src/common/find.dart
index 6bbb58b..c9b4045 100644
--- a/packages/flutter_driver/lib/src/common/find.dart
+++ b/packages/flutter_driver/lib/src/common/find.dart
@@ -120,16 +120,16 @@
 }
 
 /// A Flutter Driver command that waits until the frame is synced.
-class WaitUntilFrameSync extends Command {
+class WaitUntilNoPendingFrame extends Command {
   /// Creates a command that waits until there's no pending frame scheduled.
-  const WaitUntilFrameSync({ Duration timeout }) : super(timeout: timeout);
+  const WaitUntilNoPendingFrame({ Duration timeout }) : super(timeout: timeout);
 
   /// Deserializes this command from the value generated by [serialize].
-  WaitUntilFrameSync.deserialize(Map<String, String> json)
+  WaitUntilNoPendingFrame.deserialize(Map<String, String> json)
     : super.deserialize(json);
 
   @override
-  String get kind => 'waitUntilFrameSync';
+  String get kind => 'waitUntilNoPendingFrame';
 }
 
 /// Base class for Flutter Driver finders, objects that describe how the driver
diff --git a/packages/flutter_driver/lib/src/extension/extension.dart b/packages/flutter_driver/lib/src/extension/extension.dart
index bf9eeea..397f900 100644
--- a/packages/flutter_driver/lib/src/extension/extension.dart
+++ b/packages/flutter_driver/lib/src/extension/extension.dart
@@ -113,7 +113,7 @@
       'waitFor': _waitFor,
       'waitForAbsent': _waitForAbsent,
       'waitUntilNoTransientCallbacks': _waitUntilNoTransientCallbacks,
-      'waitUntilFrameSync': _waitUntilFrameSync,
+      'waitUntilNoPendingFrame': _waitUntilNoPendingFrame,
       'get_semantics_id': _getSemanticsId,
       'get_offset': _getOffset,
       'get_diagnostics_tree': _getDiagnosticsTree,
@@ -134,7 +134,7 @@
       'waitFor': (Map<String, String> params) => WaitFor.deserialize(params),
       'waitForAbsent': (Map<String, String> params) => WaitForAbsent.deserialize(params),
       'waitUntilNoTransientCallbacks': (Map<String, String> params) => WaitUntilNoTransientCallbacks.deserialize(params),
-      'waitUntilFrameSync': (Map<String, String> params) => WaitUntilFrameSync.deserialize(params),
+      'waitUntilNoPendingFrame': (Map<String, String> params) => WaitUntilNoPendingFrame.deserialize(params),
       'get_semantics_id': (Map<String, String> params) => GetSemanticsId.deserialize(params),
       'get_offset': (Map<String, String> params) => GetOffset.deserialize(params),
       'get_diagnostics_tree': (Map<String, String> params) => GetDiagnosticsTree.deserialize(params),
@@ -371,7 +371,7 @@
     return null;
   }
 
-  /// Returns a future that waits until frame is synced.
+  /// Returns a future that waits until no pending frame is scheduled (frame is synced).
   ///
   /// Specifically, it checks:
   /// * Whether the count of transient callbacks is zero.
@@ -388,7 +388,7 @@
   /// `set_frame_sync` method. See [FlutterDriver.runUnsynchronized] for more
   /// details on how to do this. Note, disabling frame sync will require the
   /// test author to use some other method to avoid flakiness.
-  Future<Result> _waitUntilFrameSync(Command command) async {
+  Future<Result> _waitUntilNoPendingFrame(Command command) async {
     await _waitUntilFrame(() {
       return SchedulerBinding.instance.transientCallbackCount == 0
           && !SchedulerBinding.instance.hasScheduledFrame;
diff --git a/packages/flutter_driver/test/src/extension_test.dart b/packages/flutter_driver/test/src/extension_test.dart
index 70d4b12..9b54d95 100644
--- a/packages/flutter_driver/test/src/extension_test.dart
+++ b/packages/flutter_driver/test/src/extension_test.dart
@@ -345,7 +345,7 @@
 
     testWidgets('returns immediately when frame is synced', (
         WidgetTester tester) async {
-      extension.call(const WaitUntilFrameSync().serialize())
+      extension.call(const WaitUntilNoPendingFrame().serialize())
           .then<void>(expectAsync1((Map<String, dynamic> r) {
         result = r;
       }));
@@ -366,7 +366,7 @@
         // Intentionally blank. We only care about existence of a callback.
       });
 
-      extension.call(const WaitUntilFrameSync().serialize())
+      extension.call(const WaitUntilNoPendingFrame().serialize())
           .then<void>(expectAsync1((Map<String, dynamic> r) {
         result = r;
       }));
@@ -390,7 +390,7 @@
         'waits until no pending scheduled frame', (WidgetTester tester) async {
       SchedulerBinding.instance.scheduleFrame();
 
-      extension.call(const WaitUntilFrameSync().serialize())
+      extension.call(const WaitUntilNoPendingFrame().serialize())
           .then<void>(expectAsync1((Map<String, dynamic> r) {
         result = r;
       }));