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

ui/gl/gl_context.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.
 
 #include <string>
 
 #include "base/command_line.h"
 #include "base/lazy_instance.h"
 #include "base/logging.h"
 #include "base/threading/thread_local.h"
@@ skipping 17 matching lines @@
   share_group_->AddContext(this);
 }
 
 GLContext::~GLContext() {
   share_group_->RemoveContext(this);
   if (GetCurrent() == this) {
     SetCurrent(NULL, NULL);
   }
 }
 
+bool GLContext::GetTotalGpuMemory(size_t& bytes) {
+  bytes = 0;
+  return false;
+}
+
 std::string GLContext::GetExtensions() {
   DCHECK(IsCurrent(NULL));
   const char* ext = reinterpret_cast<const char*>(glGetString(GL_EXTENSIONS));
   return std::string(ext ? ext : "");
 }
 
 bool GLContext::HasExtension(const char* name) {
   std::string extensions = GetExtensions();
   extensions += " ";
 
@@ skipping 42 matching lines @@
   static bool initialized = false;
   if (initialized)
     return initialized;
   initialized = InitializeGLExtensionBindings(GetGLImplementation(), this);
   if (!initialized)
     LOG(ERROR) << "Could not initialize extension bindings.";
   return initialized;
 }
 
 }  // namespace gfx