ozone: gbm: Add overlay support

ui/ozone/platform/dri/gbm_buffer.cc

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "ui/ozone/platform/dri/gbm_buffer.h"
 
 #include <gbm.h>
 
 #include "base/logging.h"
 #include "ui/ozone/platform/dri/dri_wrapper.h"
@@ skipping 69 matching lines @@
 }
 
 void* GbmBuffer::GetEGLClientBuffer() {
   return bo_;
 }
 
 int GbmBuffer::GetDmaBufFd() {
   return -1;
 }
 
+bool GbmBuffer::Initialize() {
+  return bo_ != NULL;
+}
+
+uint32_t GbmBuffer::GetFramebufferId() const {
+  return framebuffer_;
+}
+
+uint32_t GbmBuffer::GetHandle() const {
+  return handle_;
+}
+
+gfx::Size GbmBuffer::Size() const {
+  return size_;
+}
+
+void GbmBuffer::PreSwapBuffers() {
+}
+
+void GbmBuffer::SwapBuffers() {
+}
+
 }  // namespace ui