Implement RenderbufferGL.

BUG=angleproject:886

Change-Id: I7480943d678b2cdf6e997c3f8316acdef32f5f0d
Reviewed-on: https://chromium-review.googlesource.com/260889
Reviewed-by: Kenneth Russell <kbr@chromium.org>
Reviewed-by: Brandon Jones <bajones@chromium.org>
Tested-by: Geoff Lang <geofflang@chromium.org>
diff --git a/src/libANGLE/renderer/gl/FramebufferGL.cpp b/src/libANGLE/renderer/gl/FramebufferGL.cpp
index 08497e9..99ad76f 100644
--- a/src/libANGLE/renderer/gl/FramebufferGL.cpp
+++ b/src/libANGLE/renderer/gl/FramebufferGL.cpp
@@ -74,14 +74,11 @@
         }
         else if (attachment->type() == GL_RENDERBUFFER)
         {
-            // TODO: support RenderbufferGL
-            UNIMPLEMENTED();
+            const gl::Renderbuffer *renderbuffer = GetAs<gl::RenderbufferAttachment>(attachment)->getRenderbuffer();
+            const RenderbufferGL *renderbufferGL = GetImplAs<RenderbufferGL>(renderbuffer);
 
-            //const gl::Renderbuffer *renderbuffer = GetAs<gl::RenderbufferAttachment>(attachment)->getRenderbuffer();
-            //const RenderbufferGL *renderbufferGL = GetImplAs<RenderbufferGL>(renderbuffer);
-
-            //functions->framebufferRenderbuffer(GL_FRAMEBUFFER, attachmentPoint, GL_RENDERBUFFER,
-            //                                   renderbufferGL->getRenderbufferID());
+            functions->framebufferRenderbuffer(GL_FRAMEBUFFER, attachmentPoint, GL_RENDERBUFFER,
+                                               renderbufferGL->getRenderbufferID());
         }
         else
         {