Fix container size in case of ImageComposeScene (#1375)

Fixes JetBrains/compose-multiplatform#4875

## Testing

`:compose:ui:ui:desktopTest --tests
"androidx.compose.ui.ImageComposeSceneTest"`

## Release Notes

### Fixes - Multiple Platforms
- Fix container size for `Dialog` centering inside `ImageComposeScene`

compose/ui/ui/src/desktopTest/kotlin/androidx/compose/ui/ImageComposeSceneTest.kt

@@ -37,6 +37,7 @@ import androidx.compose.ui.test.InternalTestApi
 import androidx.compose.ui.test.junit4.DesktopScreenshotTestRule
 import androidx.compose.ui.unit.Density
 import androidx.compose.ui.unit.dp
+import androidx.compose.ui.window.Dialog
 import kotlin.time.Duration.Companion.seconds
 import kotlin.time.ExperimentalTime
 import kotlinx.coroutines.runBlocking
@@ -94,6 +95,19 @@ class ImageComposeSceneTest {
         }
     }
 
+    @Test
+    fun `run dialog in center`() {
+        val image = renderComposeScene(
+            width = 80,
+            height = 40,
+        ) {
+            Dialog(onDismissRequest = {}) {
+                Box(Modifier.size(20.dp).background(Color.Red))
+            }
+        }
+        screenshotRule.write(image)
+    }
+
     @Test
     fun `run multiple ImageComposeScene`() {
         for (i in 1..300) {

compose/ui/ui/src/skikoMain/kotlin/androidx/compose/ui/ImageComposeScene.skikoMain.kt

@@ -29,6 +29,10 @@ import androidx.compose.ui.input.pointer.PointerEventType
 import androidx.compose.ui.input.pointer.PointerKeyboardModifiers
 import androidx.compose.ui.input.pointer.PointerType
 import androidx.compose.ui.node.RootForTest
+import androidx.compose.ui.platform.PlatformContext
+import androidx.compose.ui.platform.WindowInfo
+import androidx.compose.ui.platform.WindowInfoImpl
+import androidx.compose.ui.scene.ComposeSceneContext
 import androidx.compose.ui.scene.ComposeScenePointer
 import androidx.compose.ui.scene.MultiLayerComposeScene
 import androidx.compose.ui.unit.Constraints
@@ -132,11 +136,29 @@ class ImageComposeScene @ExperimentalComposeUiApi constructor(
 
     private val surface = Surface.makeRasterN32Premul(width, height)
 
+    private val imageSize = IntSize(width, height)
+
+    private val _windowInfo = WindowInfoImpl().apply {
+        isWindowFocused = true
+        containerSize = imageSize
+    }
+
+    private val _platformContext = object : PlatformContext by PlatformContext.Empty {
+        override val windowInfo: WindowInfo
+            get() = _windowInfo
+    }
+
+    private val _sceneContext = object : ComposeSceneContext {
+        override val platformContext: PlatformContext
+            get() = _platformContext
+    }
+
     private val scene = MultiLayerComposeScene(
         density = density,
         layoutDirection = layoutDirection,
-        size = IntSize(width, height),
+        size = imageSize,
         coroutineContext = coroutineContext,
+        composeSceneContext = _sceneContext
     ).also {
         it.setContent(content = content)
     }