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..6247cf5d3812cafb17dbf8581af89d4e0c676e2d 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 +155,58 @@ void GLContextCGL::SetSwapInterval(int interval) {
   LOG(WARNING) << "GLContex: GLContextCGL::SetSwapInterval is ignored.";
 }
 
+
+bool GLContextCGL::GetTotalGpuMemory(size_t& bytes) {
+  bool got_current_gpu_memory_value = false;
+  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;

[Ken Russell (switch to Gerrit), 2012/09/20 06:47:23]

Use ScopedGenericObj parameterized with a ScopedDestroyRendererInfo function.
Refactor if necessary. See src/ui/gl/gl_context_mac.mm.

+  GLint num_renderers = 0;
+  if (CGLQueryRendererInfo(display_mask,
+                           &renderer_info,
+                           &num_renderers) != kCGLNoError)
+    return false;
+  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;
+    got_current_gpu_memory_value = true;
+    break;
+  }
+
+  CGLDestroyRendererInfo(renderer_info);
+  return got_current_gpu_memory_value;
+}
+
 GLContextCGL::~GLContextCGL() {
   Destroy();
 }