fix(android): Make FirstDrawDoneListener cleanup OnGlobalLayoutListener after use (#5567)

* fix(android): Make FirstDrawDoneListener cleanup OnGlobalLayoutListener after use

The OnGlobalLayoutListener registered in onDraw() to defer removal of the
OnDrawListener was never itself removed. In single-Activity apps (e.g. React
Native), this caused an unbounded per-navigation leak on the ViewTreeObserver,
accumulating one listener per registerForNextDraw call.

Make the OnGlobalLayoutListener remove itself after firing.

Fixes JAVA-545
Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

* changelog

---------

Co-authored-by: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

Author: romtsn

CHANGELOG.md

@@ -2,6 +2,10 @@
 
 ## Unreleased
 
+### Fixes
+
+- Fix `FirstDrawDoneListener` leaking an `OnGlobalLayoutListener` per registration ([#5567](https://github.com/getsentry/sentry-java/pull/5567))
+
 ### Features
 
 - Add experimental `SentrySQLiteDriver` to `sentry-android-sqlite` for instrumenting `androidx.sqlite.SQLiteDriver` ([#5563](https://github.com/getsentry/sentry-java/pull/5563))

sentry-android-core/src/main/java/io/sentry/android/core/internal/util/FirstDrawDoneListener.java

@@ -112,7 +112,14 @@ public void onDraw() {
     // OnDrawListeners cannot be removed within onDraw, so we remove it with a
     // GlobalLayoutListener
     view.getViewTreeObserver()
-        .addOnGlobalLayoutListener(() -> view.getViewTreeObserver().removeOnDrawListener(this));
+        .addOnGlobalLayoutListener(
+            new ViewTreeObserver.OnGlobalLayoutListener() {
+              @Override
+              public void onGlobalLayout() {
+                view.getViewTreeObserver().removeOnGlobalLayoutListener(this);
+                view.getViewTreeObserver().removeOnDrawListener(FirstDrawDoneListener.this);
+              }
+            });
     mainThreadHandler.postAtFrontOfQueue(callback);
   }
 

sentry-android-core/src/test/java/io/sentry/android/core/internal/util/FirstDrawDoneListenerTest.kt

@@ -128,6 +128,37 @@ class FirstDrawDoneListenerTest {
     assertTrue(fixture.onDrawListeners.isEmpty())
   }
 
+  @Test
+  fun `OnGlobalLayoutListener is removed after cleanup`() {
+    val view = fixture.getSut()
+
+    // Initialize mOnGlobalLayoutListeners via a dummy add/remove
+    val dummyGlobalListener = ViewTreeObserver.OnGlobalLayoutListener {}
+    view.viewTreeObserver.addOnGlobalLayoutListener(dummyGlobalListener)
+    view.viewTreeObserver.removeOnGlobalLayoutListener(dummyGlobalListener)
+
+    // CopyOnWriteArray wraps an internal ArrayList called mData
+    val copyOnWriteArray: Any = view.viewTreeObserver.getProperty("mOnGlobalLayoutListeners")
+    val mDataField = copyOnWriteArray.javaClass.getDeclaredField("mData")
+    mDataField.isAccessible = true
+
+    @Suppress("UNCHECKED_CAST")
+    fun globalLayoutListeners(): ArrayList<*> = mDataField.get(copyOnWriteArray) as ArrayList<*>
+
+    assertTrue(globalLayoutListeners().isEmpty())
+
+    FirstDrawDoneListener.registerForNextDraw(view, {}, fixture.buildInfo)
+
+    // onDraw registers a cleanup OnGlobalLayoutListener
+    view.viewTreeObserver.dispatchOnDraw()
+    assertFalse(globalLayoutListeners().isEmpty())
+
+    // onGlobalLayout fires the cleanup, which removes both the draw and layout listeners
+    view.viewTreeObserver.dispatchOnGlobalLayout()
+    assertTrue(globalLayoutListeners().isEmpty())
+    assertTrue(fixture.onDrawListeners.isEmpty())
+  }
+
   @Test
   fun `registerForNextDraw calls the given callback on the main thread after onDraw`() {
     val view = fixture.getSut()