Surface: unhide the SurfaceTexture ctor

This change unhides the Surface constructor that creates a Surface that
pushes frames to a SurfaceTexture.

Change-Id: I2e587afc52c9838d25b8681cae7421734b3e7b6e
diff --git a/api/current.txt b/api/current.txt
index e379f8b..6186d2f 100644
--- a/api/current.txt
+++ b/api/current.txt
@@ -22508,6 +22508,7 @@
   }
 
   public class Surface implements android.os.Parcelable {
+    ctor public Surface(android.graphics.SurfaceTexture);
     method public int describeContents();
     method public boolean isValid();
     method public android.graphics.Canvas lockCanvas(android.graphics.Rect) throws java.lang.IllegalArgumentException, android.view.Surface.OutOfResourcesException;
diff --git a/core/java/android/view/Surface.java b/core/java/android/view/Surface.java
index ef3d3fa5..ae81537 100644
--- a/core/java/android/view/Surface.java
+++ b/core/java/android/view/Surface.java
@@ -36,10 +36,14 @@
     public static final int ROTATION_270     = 3;
 
     /**
-     * Create Surface from a SurfaceTexture.
+     * Create Surface from a {@link SurfaceTexture}.
      *
-     * @param surfaceTexture The {@link SurfaceTexture} that is updated by this Surface.
-     * @hide
+     * Images drawn to the Surface will be made available to the {@link
+     * SurfaceTexture}, which can attach them an OpenGL ES texture via {@link
+     * SurfaceTexture#updateTexImage}.
+     *
+     * @param surfaceTexture The {@link SurfaceTexture} that is updated by this
+     * Surface.
      */
     public Surface(SurfaceTexture surfaceTexture) {
         if (DEBUG_RELEASE) {