Snap for 6694168 from 6824ce0589be8d548a27c92d4a0f4c4b6647f87b to mainline-release

Change-Id: Iaec7e5f00e87fd6bcbb21e11f2cf8fdcd55fe5ba
diff --git a/libs/nativedisplay/include/surfacetexture/surface_texture_platform.h b/libs/nativedisplay/include/surfacetexture/surface_texture_platform.h
index e2d036b..f371667 100644
--- a/libs/nativedisplay/include/surfacetexture/surface_texture_platform.h
+++ b/libs/nativedisplay/include/surfacetexture/surface_texture_platform.h
@@ -79,6 +79,8 @@
 
 /**
  * ASurfaceTexture_dequeueBuffer returns the next available AHardwareBuffer.
+ * The caller gets ownership of the buffer and need to release it with
+ * AHardwareBuffer_release.
  */
 AHardwareBuffer* ASurfaceTexture_dequeueBuffer(ASurfaceTexture* st, int* outSlotid,
                                                android_dataspace* outDataspace,
diff --git a/libs/nativedisplay/surfacetexture/surface_texture.cpp b/libs/nativedisplay/surfacetexture/surface_texture.cpp
index d1bcd8d..ebe4484 100644
--- a/libs/nativedisplay/surfacetexture/surface_texture.cpp
+++ b/libs/nativedisplay/surfacetexture/surface_texture.cpp
@@ -208,7 +208,15 @@
             *outNewContent = true;
         }
     } while (buffer.get() && (!queueEmpty));
-    return reinterpret_cast<AHardwareBuffer*>(buffer.get());
+    AHardwareBuffer* result = nullptr;
+    if (buffer.get()) {
+      result = buffer->toAHardwareBuffer();
+      // add a reference to keep the hardware buffer alive, even if
+      // BufferQueueProducer is disconnected. This is needed, because
+      // sp reference is destroyed at the end of this function.
+      AHardwareBuffer_acquire(result);
+    }
+    return result;
 }
 
 } // namespace android