diff --git a/api/current.txt b/api/current.txt
index 6de1383a2e053..3cfa0fb77f77e 100644
--- a/api/current.txt
+++ b/api/current.txt
@@ -12274,6 +12274,7 @@ package android.content.res {
     method public final void flushLayoutCache();
     method @NonNull public android.content.res.XmlResourceParser getAnimation(@AnimatorRes @AnimRes int) throws android.content.res.Resources.NotFoundException;
     method public final android.content.res.AssetManager getAssets();
+    method @AnyRes public static int getAttributeSetSourceResId(@Nullable android.util.AttributeSet);
     method public boolean getBoolean(@BoolRes int) throws android.content.res.Resources.NotFoundException;
     method @Deprecated @ColorInt public int getColor(@ColorRes int) throws android.content.res.Resources.NotFoundException;
     method @ColorInt public int getColor(@ColorRes int, @Nullable android.content.res.Resources.Theme) throws android.content.res.Resources.NotFoundException;
diff --git a/core/java/android/content/res/Resources.java b/core/java/android/content/res/Resources.java
index a2ae994f7b0f1..554e5854764e5 100644
--- a/core/java/android/content/res/Resources.java
+++ b/core/java/android/content/res/Resources.java
@@ -1396,9 +1396,11 @@ public class Resources {
 
 
     /**
+     * Returns the resource ID of the resource that was used to create this AttributeSet.
+     *
      * @param set AttributeSet for which we want to find the source.
-     * @return The resource id for the source that is backing the given AttributeSet
-     * @hide
+     * @return The resource ID for the source that is backing the given AttributeSet or
+     * {@link Resources#ID_NULL} if the AttributeSet is {@code null}.
      */
     @AnyRes
     public static int getAttributeSetSourceResId(@Nullable AttributeSet set) {