[UI] IDEA-311719, IDEA-311722 Fix togging Compact Mode with zoomed IDE

It didn't work properly before because applying new density values would override
those set by the IDE scaler, which would then break later adjustments, leading to
incorrect sizes after zooming out or resetting to the default zoom level.

GitOrigin-RevId: 722d0a4e4275f1ec6b28c4c2202b429efe59b5bf

platform/platform-impl/src/com/intellij/ide/actions/IdeScaleTransformer.kt

@@ -78,7 +78,11 @@ class IdeScaleTransformer : PersistentStateComponent<IdeScaleTransformer.Persist
     performTweaking(newParameters)
   }
 
-  private fun scale(newScaleFactor: Float, performBeforeTweaking: (() -> Unit)? = null) {
+  fun scale(newScaleFactor: Float) {
+    scale(newScaleFactor, null)
+  }
+
+  private fun scale(newScaleFactor: Float, performBeforeTweaking: (() -> Unit)?) {
     prepareTweaking()
     performBeforeTweaking?.invoke()
     val newParameters = ScalingParameters.ScaleOriented(newScaleFactor, savedOriginalConsoleFontSize)

platform/platform-impl/src/com/intellij/ide/ui/laf/LafManagerImpl.kt

@@ -648,8 +648,11 @@ class LafManagerImpl : LafManager(), PersistentStateComponent<Element>, Disposab
   }
 
   override fun applyDensity() {
+    val ideScale = IdeScaleTransformer.instance.currentScale
+    IdeScaleTransformer.instance.reset() // need to temporarily reset this to correctly apply new size values
     setCurrentLookAndFeel(currentLookAndFeel!!)
     updateUI()
+    IdeScaleTransformer.instance.scale(ideScale)
   }
 
   private fun applyDensity(defaults: UIDefaults) {