Plumb through EGL_NV_post_sub_buffer and GLX_MESA_copy_sub_buffer.

ui/gfx/gl/gl_surface_glx.cc

 // Copyright (c) 2011 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.
 
 extern "C" {
 #include <X11/Xlib.h>
 }
 
 #include "ui/gfx/gl/gl_surface_glx.h"
 
@@ skipping 185 matching lines @@
       }
     }
     if (found) {
       config_ = configs.get()[i];
     }
   }
 
   return config_;
 }
 
+bool NativeViewGLSurfaceGLX::SupportsPostSubBuffer() {
+  return g_GLX_MESA_copy_sub_buffer;
+}
+
+bool NativeViewGLSurfaceGLX::PostSubBuffer(
+    int x, int y, int width, int height) {
+  DCHECK(SupportsPostSubBuffer());
+  glXCopySubBufferMESA(g_display, window_, x, y, width, height);
+  return true;
+}
+
 PbufferGLSurfaceGLX::PbufferGLSurfaceGLX(const gfx::Size& size)
   : size_(size),
     config_(NULL),
     pbuffer_(0) {
 }
 
 PbufferGLSurfaceGLX::~PbufferGLSurfaceGLX() {
   Destroy();
 }
 
@@ skipping 70 matching lines @@
 
 void* PbufferGLSurfaceGLX::GetHandle() {
   return reinterpret_cast<void*>(pbuffer_);
 }
 
 void* PbufferGLSurfaceGLX::GetConfig() {
   return config_;
 }
 
 }  // namespace gfx