Get real GPU memory values on NV+Linux and OS X

ui/gl/gl_context_glx.cc

 // Copyright (c) 2012 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/gl/gl_context_glx.h"
 
@@ skipping 226 matching lines @@
 std::string GLContextGLX::GetExtensions() {
   DCHECK(IsCurrent(NULL));
   const char* extensions = GLSurfaceGLX::GetGLXExtensions();
   if (extensions) {
     return GLContext::GetExtensions() + " " + extensions;
   }
 
   return GLContext::GetExtensions();
 }
 
+bool GLContextGLX::GetTotalGpuMemory(size_t& bytes) {
+  bytes = 0;
+  if (HasExtension("GL_NVX_gpu_memory_info")) {
+    GLint kbytes = 0;
+    glGetIntegerv(GL_GPU_MEMORY_INFO_DEDICATED_VIDMEM_NVX, &kbytes);
+    bytes = 1024*kbytes;
+    return true;
+  }
+  return false;
+}
+
 bool GLContextGLX::WasAllocatedUsingRobustnessExtension() {
   return GLSurfaceGLX::IsCreateContextRobustnessSupported();
 }
 
 GLContextGLX::~GLContextGLX() {
   Destroy();
 }
 
 }  // namespace gfx