diff --git a/libs/WindowManager/Shell/tests/flicker/src/com/android/wm/shell/flicker/CommonAssertions.kt b/libs/WindowManager/Shell/tests/flicker/src/com/android/wm/shell/flicker/CommonAssertions.kt
index 1e4d23c924e7e..9da51796a8c1c 100644
--- a/libs/WindowManager/Shell/tests/flicker/src/com/android/wm/shell/flicker/CommonAssertions.kt
+++ b/libs/WindowManager/Shell/tests/flicker/src/com/android/wm/shell/flicker/CommonAssertions.kt
@@ -20,6 +20,7 @@ package com.android.wm.shell.flicker
 import android.view.Surface
 import com.android.server.wm.flicker.FlickerTestParameter
 import com.android.server.wm.flicker.helpers.WindowUtils
+import com.android.server.wm.flicker.traces.layers.LayersTraceSubject
 import com.android.server.wm.traces.common.IComponentMatcher
 import com.android.server.wm.traces.common.region.Region
 
@@ -88,18 +89,13 @@ fun FlickerTestParameter.splitAppLayerBoundsBecomesVisible(
     splitLeftTop: Boolean
 ) {
     assertLayers {
-        val dividerRegion = this.last().layer(SPLIT_SCREEN_DIVIDER_COMPONENT).visibleRegion.region
         this.isInvisible(component)
             .then()
-            .invoke("splitAppLayerBoundsBecomesVisible") {
-                it.visibleRegion(component).coversAtMost(
-                    if (splitLeftTop) {
-                        getSplitLeftTopRegion(dividerRegion, endRotation)
-                    } else {
-                        getSplitRightBottomRegion(dividerRegion, endRotation)
-                    }
-                )
-            }
+            .isInvisible(SPLIT_SCREEN_DIVIDER_COMPONENT)
+            .isVisible(component)
+            .then()
+            .isVisible(SPLIT_SCREEN_DIVIDER_COMPONENT)
+            .splitAppLayerBoundsSnapToDivider(component, splitLeftTop, endRotation)
     }
 }
 
@@ -108,16 +104,7 @@ fun FlickerTestParameter.splitAppLayerBoundsBecomesInvisible(
     splitLeftTop: Boolean
 ) {
     assertLayers {
-        val dividerRegion = this.first().layer(SPLIT_SCREEN_DIVIDER_COMPONENT).visibleRegion.region
-        this.invoke("splitAppLayerBoundsBecomesVisible") {
-                it.visibleRegion(component).coversAtMost(
-                    if (splitLeftTop) {
-                        getSplitLeftTopRegion(dividerRegion, endRotation)
-                    } else {
-                        getSplitRightBottomRegion(dividerRegion, endRotation)
-                    }
-                )
-            }
+        this.splitAppLayerBoundsSnapToDivider(component, splitLeftTop, endRotation)
             .then()
             .isVisible(component, true)
             .then()
@@ -141,6 +128,40 @@ fun FlickerTestParameter.splitAppLayerBoundsIsVisibleAtEnd(
     }
 }
 
+fun FlickerTestParameter.splitAppLayerBoundsChanges(
+    component: IComponentMatcher,
+    splitLeftTop: Boolean
+) {
+    assertLayers {
+        if (splitLeftTop) {
+            this.splitAppLayerBoundsSnapToDivider(component, splitLeftTop, endRotation)
+                .then()
+                .isInvisible(component)
+                .then()
+                .splitAppLayerBoundsSnapToDivider(component, splitLeftTop, endRotation)
+        } else {
+            this.splitAppLayerBoundsSnapToDivider(component, splitLeftTop, endRotation)
+        }
+    }
+}
+
+fun LayersTraceSubject.splitAppLayerBoundsSnapToDivider(
+    component: IComponentMatcher,
+    splitLeftTop: Boolean,
+    rotation: Int
+): LayersTraceSubject {
+    return invoke("splitAppLayerBoundsSnapToDivider") {
+        val dividerRegion = it.layer(SPLIT_SCREEN_DIVIDER_COMPONENT).visibleRegion.region
+        it.visibleRegion(component).coversAtMost(
+            if (splitLeftTop) {
+                getSplitLeftTopRegion(dividerRegion, rotation)
+            } else {
+                getSplitRightBottomRegion(dividerRegion, rotation)
+            }
+        )
+    }
+}
+
 fun FlickerTestParameter.appWindowBecomesVisible(
     component: IComponentMatcher
 ) {
diff --git a/libs/WindowManager/Shell/tests/flicker/src/com/android/wm/shell/flicker/CommonConstants.kt b/libs/WindowManager/Shell/tests/flicker/src/com/android/wm/shell/flicker/CommonConstants.kt
index 3708e5f65485f..8b717a0cb75ef 100644
--- a/libs/WindowManager/Shell/tests/flicker/src/com/android/wm/shell/flicker/CommonConstants.kt
+++ b/libs/WindowManager/Shell/tests/flicker/src/com/android/wm/shell/flicker/CommonConstants.kt
@@ -23,3 +23,4 @@ const val SYSTEM_UI_PACKAGE_NAME = "com.android.systemui"
 val APP_PAIR_SPLIT_DIVIDER_COMPONENT = ComponentMatcher("", "AppPairSplitDivider#")
 val DOCKED_STACK_DIVIDER_COMPONENT = ComponentMatcher("", "DockedStackDivider#")
 val SPLIT_SCREEN_DIVIDER_COMPONENT = ComponentMatcher("", "StageCoordinatorSplitDivider#")
+val SPLIT_DECOR_MANAGER = ComponentMatcher("", "SplitDecorManager#")
diff --git a/libs/WindowManager/Shell/tests/flicker/src/com/android/wm/shell/flicker/helpers/SplitScreenHelper.kt b/libs/WindowManager/Shell/tests/flicker/src/com/android/wm/shell/flicker/helpers/SplitScreenHelper.kt
index 4877442bacf7c..42b7b1162d93a 100644
--- a/libs/WindowManager/Shell/tests/flicker/src/com/android/wm/shell/flicker/helpers/SplitScreenHelper.kt
+++ b/libs/WindowManager/Shell/tests/flicker/src/com/android/wm/shell/flicker/helpers/SplitScreenHelper.kt
@@ -30,6 +30,7 @@ import com.android.launcher3.tapl.LauncherInstrumentation
 import com.android.server.wm.traces.common.IComponentMatcher
 import com.android.server.wm.traces.parser.toFlickerComponent
 import com.android.server.wm.traces.parser.windowmanager.WindowManagerStateHelper
+import com.android.wm.shell.flicker.SPLIT_DECOR_MANAGER
 import com.android.wm.shell.flicker.SYSTEM_UI_PACKAGE_NAME
 import com.android.wm.shell.flicker.testapp.Components
 
@@ -220,6 +221,23 @@ class SplitScreenHelper(
             }
         }
 
+        fun dragDividerToResizeAndWait(
+            device: UiDevice,
+            wmHelper: WindowManagerStateHelper
+        ) {
+            val displayBounds = wmHelper.currentState.layerState
+                .displays.firstOrNull { !it.isVirtual }
+                ?.layerStackSpace
+                ?: error("Display not found")
+            val dividerBar = device.wait(Until.findObject(dividerBarSelector), TIMEOUT_MS)
+            dividerBar.drag(Point(displayBounds.width * 2 / 3, displayBounds.height * 2 / 3))
+
+            wmHelper.StateSyncBuilder()
+                .withAppTransitionIdle()
+                .withWindowSurfaceDisappeared(SPLIT_DECOR_MANAGER)
+                .waitForAndVerify()
+        }
+
         fun dragDividerToDismissSplit(
             device: UiDevice,
             wmHelper: WindowManagerStateHelper
diff --git a/libs/WindowManager/Shell/tests/flicker/src/com/android/wm/shell/flicker/splitscreen/DragDividerToResize.kt b/libs/WindowManager/Shell/tests/flicker/src/com/android/wm/shell/flicker/splitscreen/DragDividerToResize.kt
new file mode 100644
index 0000000000000..cf2dc39637df6
--- /dev/null
+++ b/libs/WindowManager/Shell/tests/flicker/src/com/android/wm/shell/flicker/splitscreen/DragDividerToResize.kt
@@ -0,0 +1,210 @@
+/*
+ * Copyright (C) 2022 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.android.wm.shell.flicker.splitscreen
+
+import android.platform.test.annotations.Postsubmit
+import android.platform.test.annotations.Presubmit
+import android.view.Surface
+import android.view.WindowManagerPolicyConstants
+import androidx.test.filters.RequiresDevice
+import com.android.server.wm.flicker.FlickerParametersRunnerFactory
+import com.android.server.wm.flicker.FlickerTestParameter
+import com.android.server.wm.flicker.FlickerTestParameterFactory
+import com.android.server.wm.flicker.annotation.Group1
+import com.android.server.wm.flicker.dsl.FlickerBuilder
+import com.android.wm.shell.flicker.SPLIT_SCREEN_DIVIDER_COMPONENT
+import com.android.wm.shell.flicker.helpers.SplitScreenHelper
+import com.android.wm.shell.flicker.splitAppLayerBoundsChanges
+import org.junit.Assume
+import org.junit.Before
+import org.junit.FixMethodOrder
+import org.junit.Test
+import org.junit.runner.RunWith
+import org.junit.runners.MethodSorters
+import org.junit.runners.Parameterized
+
+/**
+ * Test resize split by dragging the divider bar.
+ *
+ * To run this test: `atest WMShellFlickerTests:DragDividerToResize`
+ */
+@RequiresDevice
+@RunWith(Parameterized::class)
+@Parameterized.UseParametersRunnerFactory(FlickerParametersRunnerFactory::class)
+@FixMethodOrder(MethodSorters.NAME_ASCENDING)
+@Group1
+class DragDividerToResize (testSpec: FlickerTestParameter) : SplitScreenBase(testSpec) {
+
+    // TODO(b/231399940): Remove this once we can use recent shortcut to enter split.
+    @Before
+    open fun before() {
+        Assume.assumeTrue(tapl.isTablet)
+    }
+
+    override val transition: FlickerBuilder.() -> Unit
+        get() = {
+            super.transition(this)
+            setup {
+                eachRun {
+                    tapl.goHome()
+                    primaryApp.launchViaIntent(wmHelper)
+                    // TODO(b/231399940): Use recent shortcut to enter split.
+                    tapl.launchedAppState.taskbar
+                        .openAllApps()
+                        .getAppIcon(secondaryApp.appName)
+                        .dragToSplitscreen(secondaryApp.`package`, primaryApp.`package`)
+                    SplitScreenHelper.waitForSplitComplete(wmHelper, primaryApp, secondaryApp)
+                }
+            }
+            transitions {
+                SplitScreenHelper.dragDividerToResizeAndWait(device, wmHelper)
+            }
+        }
+
+    @Presubmit
+    @Test
+    fun splitScreenDividerKeepVisible() {
+        testSpec.assertLayers {
+            this.isVisible(SPLIT_SCREEN_DIVIDER_COMPONENT)
+        }
+    }
+
+    @Presubmit
+    @Test
+    fun primaryAppLayerKeepVisible() {
+        testSpec.assertLayers {
+            this.isVisible(primaryApp)
+        }
+    }
+
+    @Presubmit
+    @Test
+    fun secondaryAppLayerVisibilityChanges() {
+        testSpec.assertLayers {
+            this.isVisible(secondaryApp)
+                .then()
+                .isInvisible(secondaryApp)
+                .then()
+                .isVisible(secondaryApp)
+        }
+    }
+
+    @Presubmit
+    @Test
+    fun primaryAppWindowKeepVisible() {
+        testSpec.assertWm {
+            this.isAppWindowVisible(primaryApp)
+        }
+    }
+
+    @Presubmit
+    @Test
+    fun secondaryAppWindowKeepVisible() {
+        testSpec.assertWm {
+            this.isAppWindowVisible(secondaryApp)
+        }
+    }
+
+    @Presubmit
+    @Test
+    fun primaryAppBoundsChanges() = testSpec.splitAppLayerBoundsChanges(
+        primaryApp, splitLeftTop = false)
+
+    @Presubmit
+    @Test
+    fun secondaryAppBoundsChanges() = testSpec.splitAppLayerBoundsChanges(
+        secondaryApp, splitLeftTop = true)
+
+    /** {@inheritDoc} */
+    @Postsubmit
+    @Test
+    override fun entireScreenCovered() =
+        super.entireScreenCovered()
+
+    /** {@inheritDoc} */
+    @Postsubmit
+    @Test
+    override fun navBarLayerIsVisibleAtStartAndEnd() =
+        super.navBarLayerIsVisibleAtStartAndEnd()
+
+    /** {@inheritDoc} */
+    @Postsubmit
+    @Test
+    override fun navBarLayerPositionAtStartAndEnd() =
+        super.navBarLayerPositionAtStartAndEnd()
+
+    /** {@inheritDoc} */
+    @Postsubmit
+    @Test
+    override fun navBarWindowIsAlwaysVisible() =
+        super.navBarWindowIsAlwaysVisible()
+
+    /** {@inheritDoc} */
+    @Postsubmit
+    @Test
+    override fun statusBarLayerIsVisibleAtStartAndEnd() =
+        super.statusBarLayerIsVisibleAtStartAndEnd()
+
+    /** {@inheritDoc} */
+    @Postsubmit
+    @Test
+    override fun statusBarLayerPositionAtStartAndEnd() =
+        super.statusBarLayerPositionAtStartAndEnd()
+
+    /** {@inheritDoc} */
+    @Postsubmit
+    @Test
+    override fun statusBarWindowIsAlwaysVisible() =
+        super.statusBarWindowIsAlwaysVisible()
+
+    /** {@inheritDoc} */
+    @Postsubmit
+    @Test
+    override fun taskBarLayerIsVisibleAtStartAndEnd() =
+        super.taskBarLayerIsVisibleAtStartAndEnd()
+
+    /** {@inheritDoc} */
+    @Postsubmit
+    @Test
+    override fun taskBarWindowIsAlwaysVisible() =
+        super.taskBarWindowIsAlwaysVisible()
+
+    /** {@inheritDoc} */
+    @Postsubmit
+    @Test
+    override fun visibleLayersShownMoreThanOneConsecutiveEntry() =
+        super.visibleLayersShownMoreThanOneConsecutiveEntry()
+
+    /** {@inheritDoc} */
+    @Postsubmit
+    @Test
+    override fun visibleWindowsShownMoreThanOneConsecutiveEntry() =
+        super.visibleWindowsShownMoreThanOneConsecutiveEntry()
+
+    companion object {
+        @Parameterized.Parameters(name = "{0}")
+        @JvmStatic
+        fun getParams(): List<FlickerTestParameter> {
+            return FlickerTestParameterFactory.getInstance().getConfigNonRotationTests(
+                repetitions = SplitScreenHelper.TEST_REPETITIONS,
+                supportedRotations = listOf(Surface.ROTATION_0),
+                // TODO(b/176061063):The 3 buttons of nav bar do not exist in the hierarchy.
+                supportedNavigationModes =
+                listOf(WindowManagerPolicyConstants.NAV_BAR_MODE_GESTURAL_OVERLAY))
+        }
+    }
+}
diff --git a/libs/WindowManager/Shell/tests/flicker/src/com/android/wm/shell/flicker/splitscreen/SwitchBackToSplitFromHome.kt b/libs/WindowManager/Shell/tests/flicker/src/com/android/wm/shell/flicker/splitscreen/SwitchBackToSplitFromHome.kt
index c48f3f77858b2..f69eb8f06182b 100644
--- a/libs/WindowManager/Shell/tests/flicker/src/com/android/wm/shell/flicker/splitscreen/SwitchBackToSplitFromHome.kt
+++ b/libs/WindowManager/Shell/tests/flicker/src/com/android/wm/shell/flicker/splitscreen/SwitchBackToSplitFromHome.kt
@@ -30,7 +30,6 @@ import com.android.wm.shell.flicker.appWindowIsVisibleAtEnd
 import com.android.wm.shell.flicker.helpers.SplitScreenHelper
 import com.android.wm.shell.flicker.layerBecomesVisible
 import com.android.wm.shell.flicker.layerIsVisibleAtEnd
-import com.android.wm.shell.flicker.splitAppLayerBoundsBecomesVisible
 import com.android.wm.shell.flicker.splitAppLayerBoundsIsVisibleAtEnd
 import com.android.wm.shell.flicker.splitScreenDividerBecomesVisible
 import org.junit.Assume
@@ -104,7 +103,7 @@ class SwitchBackToSplitFromHome(testSpec: FlickerTestParameter) : SplitScreenBas
 
     @Presubmit
     @Test
-    fun secondaryAppBoundsBecomesVisible() = testSpec.splitAppLayerBoundsBecomesVisible(
+    fun secondaryAppBoundsIsVisibleAtEnd() = testSpec.splitAppLayerBoundsIsVisibleAtEnd(
         secondaryApp, splitLeftTop = true)
 
     @Presubmit