diff --git a/wear/watchface/watchface-client-guava/src/androidTest/java/androidx/wear/watchface/client/guava/ListenableWatchFaceMetadataClientTest.kt b/wear/watchface/watchface-client-guava/src/androidTest/java/androidx/wear/watchface/client/guava/ListenableWatchFaceMetadataClientTest.kt
index 2c071f6..98ce3be 100644
--- a/wear/watchface/watchface-client-guava/src/androidTest/java/androidx/wear/watchface/client/guava/ListenableWatchFaceMetadataClientTest.kt
+++ b/wear/watchface/watchface-client-guava/src/androidTest/java/androidx/wear/watchface/client/guava/ListenableWatchFaceMetadataClientTest.kt
@@ -22,9 +22,7 @@
 import android.content.Context
 import android.content.Intent
 import android.content.res.XmlResourceParser
-import android.os.Handler
 import android.os.IBinder
-import android.os.Looper
 import androidx.test.core.app.ApplicationProvider
 import androidx.test.ext.junit.runners.AndroidJUnit4
 import androidx.test.filters.MediumTest
@@ -36,6 +34,7 @@
 import org.junit.Test
 import org.junit.runner.RunWith
 import java.util.concurrent.TimeUnit
+import kotlinx.coroutines.MainScope
 
 private const val TIMEOUT_MS = 500L
 
@@ -47,7 +46,7 @@
     private val realService = object : WatchFaceControlService() {
         @SuppressLint("NewApi")
         override fun createServiceStub(): IWatchFaceInstanceServiceStub =
-            IWatchFaceInstanceServiceStub(this, Handler(Looper.getMainLooper()))
+            IWatchFaceInstanceServiceStub(this, MainScope())
 
         init {
             setContext(ApplicationProvider.getApplicationContext<Context>())
diff --git a/wear/watchface/watchface-client/src/androidTest/java/androidx/wear/watchface/client/test/WatchFaceControlClientTest.kt b/wear/watchface/watchface-client/src/androidTest/java/androidx/wear/watchface/client/test/WatchFaceControlClientTest.kt
index 1220dfe..0dd334c 100644
--- a/wear/watchface/watchface-client/src/androidTest/java/androidx/wear/watchface/client/test/WatchFaceControlClientTest.kt
+++ b/wear/watchface/watchface-client/src/androidTest/java/androidx/wear/watchface/client/test/WatchFaceControlClientTest.kt
@@ -751,14 +751,9 @@
             ]!!
         }
 
-        var isFirstCall = true
         handlerCoroutineScope.launch {
             leftComplicationSlot.complicationData.collect {
-                if (!isFirstCall) {
-                    updateCountDownLatch.countDown()
-                } else {
-                    isFirstCall = false
-                }
+                updateCountDownLatch.countDown()
             }
         }
 
diff --git a/wear/watchface/watchface-client/src/androidTest/java/androidx/wear/watchface/client/test/WatchFaceControlTestService.kt b/wear/watchface/watchface-client/src/androidTest/java/androidx/wear/watchface/client/test/WatchFaceControlTestService.kt
index 98b337e..621ae29 100644
--- a/wear/watchface/watchface-client/src/androidTest/java/androidx/wear/watchface/client/test/WatchFaceControlTestService.kt
+++ b/wear/watchface/watchface-client/src/androidTest/java/androidx/wear/watchface/client/test/WatchFaceControlTestService.kt
@@ -20,13 +20,12 @@
 import android.content.Context
 import android.content.Intent
 import android.os.Build
-import android.os.Handler
 import android.os.IBinder
-import android.os.Looper
 import androidx.annotation.RequiresApi
 import androidx.test.core.app.ApplicationProvider
 import androidx.wear.watchface.control.IWatchFaceInstanceServiceStub
 import androidx.wear.watchface.control.WatchFaceControlService
+import kotlinx.coroutines.MainScope
 
 /**
  * Test shim to allow us to connect to WatchFaceControlService from
@@ -42,9 +41,7 @@
 
     private val realService = object : WatchFaceControlService() {
         override fun createServiceStub(): IWatchFaceInstanceServiceStub =
-            object : IWatchFaceInstanceServiceStub(
-                this@WatchFaceControlTestService, Handler(Looper.getMainLooper())
-            ) {
+            object : IWatchFaceInstanceServiceStub(this@WatchFaceControlTestService, MainScope()) {
                 @RequiresApi(Build.VERSION_CODES.O_MR1)
                 override fun getApiVersion(): Int = apiVersionOverride ?: super.getApiVersion()
             }
diff --git a/wear/watchface/watchface-guava/src/androidTest/java/androidx/wear/watchface/WatchFaceControlTestService.kt b/wear/watchface/watchface-guava/src/androidTest/java/androidx/wear/watchface/WatchFaceControlTestService.kt
index 65312b5..9cdf97c 100644
--- a/wear/watchface/watchface-guava/src/androidTest/java/androidx/wear/watchface/WatchFaceControlTestService.kt
+++ b/wear/watchface/watchface-guava/src/androidTest/java/androidx/wear/watchface/WatchFaceControlTestService.kt
@@ -44,6 +44,7 @@
 import java.util.concurrent.CountDownLatch
 import java.util.concurrent.TimeUnit
 import java.util.concurrent.TimeoutException
+import kotlinx.coroutines.MainScope
 
 internal const val TIMEOUT_MILLIS = 1000L
 
@@ -64,7 +65,7 @@
         override fun createServiceStub(): IWatchFaceInstanceServiceStub =
             object : IWatchFaceInstanceServiceStub(
                 ApplicationProvider.getApplicationContext<Context>(),
-                Handler(Looper.getMainLooper())
+                MainScope()
             ) {
                 @RequiresApi(Build.VERSION_CODES.O_MR1)
                 override fun getApiVersion(): Int = apiVersionOverride ?: super.getApiVersion()
diff --git a/wear/watchface/watchface/src/main/java/androidx/wear/watchface/WatchFaceService.kt b/wear/watchface/watchface/src/main/java/androidx/wear/watchface/WatchFaceService.kt
index 8a4926a..cfc5e8b 100644
--- a/wear/watchface/watchface/src/main/java/androidx/wear/watchface/WatchFaceService.kt
+++ b/wear/watchface/watchface/src/main/java/androidx/wear/watchface/WatchFaceService.kt
@@ -84,7 +84,6 @@
 import kotlinx.coroutines.Runnable
 import kotlinx.coroutines.android.asCoroutineDispatcher
 import kotlinx.coroutines.cancel
-import kotlinx.coroutines.flow.collect
 import kotlinx.coroutines.launch
 import kotlinx.coroutines.runBlocking
 import java.io.ByteArrayInputStream
@@ -96,7 +95,6 @@
 import java.io.ObjectOutputStream
 import java.io.PrintWriter
 import java.time.Instant
-import java.util.concurrent.CountDownLatch
 import kotlinx.coroutines.CancellationException
 import kotlinx.coroutines.withContext
 
@@ -2399,50 +2397,6 @@
 }
 
 /**
- * Runs the supplied task on the handler thread. If we're not on the handler thread a task is posted
- * and we block until it's been processed.
- *
- * AIDL calls are dispatched from a thread pool, but for simplicity WatchFaceImpl code is largely
- * single threaded so we need to post tasks to the UI thread and wait for them to execute.
- *
- * @param traceEventName The name of the trace event to emit.
- * @param task The task to post on the handler.
- * @return [R] the return value of [task].
- */
-internal fun <R> Handler.runBlockingOnHandlerWithTracing(
-    traceEventName: String,
-    task: () -> R
-): R = TraceEvent(traceEventName).use {
-    if (looper == Looper.myLooper()) {
-        task.invoke()
-    } else {
-        val latch = CountDownLatch(1)
-        var returnVal: R? = null
-        var exception: Exception? = null
-        if (post {
-            try {
-                returnVal = TraceEvent("$traceEventName invokeTask").use {
-                    task.invoke()
-                }
-            } catch (e: Exception) {
-                // Will rethrow on the calling thread.
-                exception = e
-            }
-            latch.countDown()
-        }
-        ) {
-            latch.await()
-            if (exception != null) {
-                throw exception as Exception
-            }
-        }
-        // R might be nullable so we can't assert nullability here.
-        @Suppress("UNCHECKED_CAST")
-        returnVal as R
-    }
-}
-
-/**
  * Runs the supplied task on the handler thread. If we're not on the handler thread a task is
  * posted.
  *
@@ -2472,19 +2426,16 @@
     traceEventName: String,
     task: suspend () -> R
 ): R = TraceEvent(traceEventName).use {
-    val latch = CountDownLatch(1)
-    var r: R? = null
-    launch {
-        try {
-            r = task()
-        } catch (e: Exception) {
-            Log.e("CoroutineScope", "Exception in traceEventName", e)
-            throw e
+    try {
+        return runBlocking {
+            withContext(coroutineContext) {
+                task()
+            }
         }
-        latch.countDown()
+    } catch (e: Exception) {
+        Log.e("CoroutineScope", "Exception in traceEventName", e)
+        throw e
     }
-    latch.await()
-    return r!!
 }
 
 /**
diff --git a/wear/watchface/watchface/src/main/java/androidx/wear/watchface/control/WatchFaceControlService.kt b/wear/watchface/watchface/src/main/java/androidx/wear/watchface/control/WatchFaceControlService.kt
index ed79006..544256e 100644
--- a/wear/watchface/watchface/src/main/java/androidx/wear/watchface/control/WatchFaceControlService.kt
+++ b/wear/watchface/watchface/src/main/java/androidx/wear/watchface/control/WatchFaceControlService.kt
@@ -20,9 +20,7 @@
 import android.content.ComponentName
 import android.content.Context
 import android.content.Intent
-import android.os.Handler
 import android.os.IBinder
-import android.os.Looper
 import android.util.Log
 import androidx.annotation.RequiresApi
 import androidx.annotation.RestrictTo
@@ -42,11 +40,13 @@
 import androidx.wear.watchface.control.data.WallpaperInteractiveWatchFaceInstanceParams
 import androidx.wear.watchface.data.ComplicationSlotMetadataWireFormat
 import androidx.wear.watchface.editor.EditorService
-import androidx.wear.watchface.runBlockingOnHandlerWithTracing
+import androidx.wear.watchface.runBlockingWithTracing
 import androidx.wear.watchface.style.data.UserStyleFlavorsWireFormat
 import androidx.wear.watchface.style.data.UserStyleSchemaWireFormat
 import java.io.FileDescriptor
 import java.io.PrintWriter
+import kotlinx.coroutines.CoroutineScope
+import kotlinx.coroutines.MainScope
 
 /**
  * A service for creating and controlling watch face instances.
@@ -77,7 +77,7 @@
     @VisibleForTesting
     public open fun createServiceStub(): IWatchFaceInstanceServiceStub =
         TraceEvent("WatchFaceControlService.createServiceStub").use {
-            IWatchFaceInstanceServiceStub(this, Handler(Looper.getMainLooper()))
+            IWatchFaceInstanceServiceStub(this, MainScope())
         }
 
     @VisibleForTesting
@@ -95,29 +95,12 @@
     }
 }
 
-/**
- * Factory for use by on watch face editors to create [IWatchFaceControlService].
- *
- * @hide
- */
-@RestrictTo(RestrictTo.Scope.LIBRARY_GROUP)
-@RequiresApi(27)
-public class WatchFaceControlServiceFactory {
-    public companion object {
-        @JvmStatic
-        public fun createWatchFaceControlService(
-            context: Context,
-            uiThreadHandler: Handler
-        ): IWatchFaceControlService = IWatchFaceInstanceServiceStub(context, uiThreadHandler)
-    }
-}
-
 /** @hide */
 @RequiresApi(27)
 @RestrictTo(RestrictTo.Scope.LIBRARY_GROUP)
 public open class IWatchFaceInstanceServiceStub(
     private val context: Context,
-    private val uiThreadHandler: Handler
+    private val uiThreadCoroutineScope: CoroutineScope
 ) : IWatchFaceControlService.Stub() {
     override fun getApiVersion(): Int = IWatchFaceControlService.API_VERSION
 
@@ -139,7 +122,7 @@
         val engine = createHeadlessEngine(params.watchFaceName, context)
         engine?.let {
             // This is serviced on a background thread so it should be fine to block.
-            uiThreadHandler.runBlockingOnHandlerWithTracing("createHeadlessInstance") {
+            uiThreadCoroutineScope.runBlockingWithTracing("createHeadlessInstance") {
                 // However the WatchFaceService.createWatchFace method needs to be run on the UI
                 // thread.
                 it.createHeadlessInstance(params)