Remove obsolete Renderbuffer types.

RenderbufferProxySet and FramebufferTextureBindingPointer aren't
necessary any more with our refactored renderbuffer classes and
ownership of attachments by the Framebuffer.

We can also consolidate the FramebufferAttachment and implementation
to a single class, and no longer need to store ref counted objects
in the Framebuffer class directly.

BUG=angle:660

Change-Id: Idcc06dfb42b47242b33494e797a0ba06d6669511
Reviewed-on: https://chromium-review.googlesource.com/201838
Tested-by: Jamie Madill <jmadill@chromium.org>
Reviewed-by: Geoff Lang <geofflang@chromium.org>
diff --git a/src/libGLESv2/Renderbuffer.h b/src/libGLESv2/Renderbuffer.h
index ef7989e..51c1eeb 100644
--- a/src/libGLESv2/Renderbuffer.h
+++ b/src/libGLESv2/Renderbuffer.h
@@ -17,7 +17,6 @@
 
 #include "common/angleutils.h"
 #include "common/RefCountObject.h"
-#include "libGLESv2/FramebufferAttachment.h"
 
 namespace rx
 {
@@ -30,6 +29,7 @@
 namespace gl
 {
 class RenderbufferStorage;
+class FramebufferAttachment;
 
 // A GL renderbuffer object is usually used as a depth or stencil buffer attachment
 // for a framebuffer object. The renderbuffer itself is a distinct GL object, see