Implement drawLayers() with buffer source.

Bug: 118461793
Change-Id: Icce51ba6d7f31ff370fb281867c7b663449543a6
Test: librenderengine_test
diff --git a/libs/renderengine/gl/GLESRenderEngine.h b/libs/renderengine/gl/GLESRenderEngine.h
index b6fff33..2af2aed 100644
--- a/libs/renderengine/gl/GLESRenderEngine.h
+++ b/libs/renderengine/gl/GLESRenderEngine.h
@@ -127,6 +127,7 @@
     // Defines the viewport, and sets the projection matrix to the projection
     // defined by the clip.
     void setViewportAndProjection(Rect viewport, Rect clip);
+    status_t bindExternalTextureBuffer(uint32_t texName, sp<GraphicBuffer> buffer, sp<Fence> fence);
 
     EGLDisplay mEGLDisplay;
     EGLConfig mEGLConfig;