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

ui/gl/gl_context_cgl.cc

Index: ui/gl/gl_context_cgl.cc
diff --git a/ui/gl/gl_context_cgl.cc b/ui/gl/gl_context_cgl.cc
index 8affe56f683a97bd7cb56aa072337b16e09842c1..1f79ea0eb0b6b308d6cb031b65f5c3acc8c4ae98 100644
--- a/ui/gl/gl_context_cgl.cc
+++ b/ui/gl/gl_context_cgl.cc
@@ -5,6 +5,7 @@
 #include "ui/gl/gl_context_cgl.h"
 
 #include <OpenGL/CGLRenderers.h>
+#include <OpenGL/CGLTypes.h>
 #include <vector>
 
 #include "base/debug/trace_event.h"
@@ -154,6 +155,59 @@ void GLContextCGL::SetSwapInterval(int interval) {
   LOG(WARNING) << "GLContex: GLContextCGL::SetSwapInterval is ignored.";
 }
 
+
+bool GLContextCGL::GetTotalGpuMemory(size_t* bytes) {
+  DCHECK(bytes);
+  *bytes = 0;
+
+  CGLContextObj context = reinterpret_cast<CGLContextObj>(context_);
+  if (!context)
+    return false;
+
+  // Retrieve the current renderer ID
+  GLint current_renderer_id = 0;
+  if (CGLGetParameter(context,
+                      kCGLCPCurrentRendererID,
+                      &current_renderer_id) != kCGLNoError)
+    return false;
+
+  // Iterate through the list of all renderers
+  GLuint display_mask = static_cast<GLuint>(-1);
+  CGLRendererInfoObj renderer_info = NULL;
+  GLint num_renderers = 0;
+  if (CGLQueryRendererInfo(display_mask,
+                           &renderer_info,
+                           &num_renderers) != kCGLNoError)
+    return false;
+
+  ScopedCGLRendererInfoObj scoper(renderer_info);
+
+  for (GLint renderer_index = 0;
+       renderer_index < num_renderers;
+       ++renderer_index) {
+    // Skip this if this renderer is not the current renderer.
+    GLint renderer_id = 0;
+    if (CGLDescribeRenderer(renderer_info,
+                            renderer_index,
+                            kCGLRPRendererID,
+                            &renderer_id) != kCGLNoError)
+        continue;
+    if (renderer_id != current_renderer_id)
+        continue;
+    // Retrieve the video memory for the renderer.
+    GLint video_memory = 0;
+    if (CGLDescribeRenderer(renderer_info,
+                            renderer_index,
+                            kCGLRPVideoMemory,
+                            &video_memory) != kCGLNoError)
+        continue;
+    *bytes = video_memory;
+    return true;
+  }
+
+  return false;
+}
+
 GLContextCGL::~GLContextCGL() {
   Destroy();
 }
@@ -173,4 +227,8 @@ void GLContextCGL::ForceUseOfDiscreteGPU() {
   // format is deliberately leaked.
 }
 
+void ScopedCGLDestroyRendererInfo::operator()(CGLRendererInfoObj x) const {
+  CGLDestroyRendererInfo(x);
+}
+
 }  // namespace gfx