Add GPU memory tab to the task manager.

chrome/browser/ui/gtk/task_manager_gtk.h

Index: chrome/browser/ui/gtk/task_manager_gtk.h
diff --git a/chrome/browser/ui/gtk/task_manager_gtk.h b/chrome/browser/ui/gtk/task_manager_gtk.h
index 677bc93010f09f25600617dd6bb059fb51b100f4..399aeba5ff58147c444d137611c9f7efc0a567f4 100644
--- a/chrome/browser/ui/gtk/task_manager_gtk.h
+++ b/chrome/browser/ui/gtk/task_manager_gtk.h
@@ -185,6 +185,13 @@ class TaskManagerGtk : public TaskManagerModelObserver {
         CompareImpl(model, a, b, IDS_TASK_MANAGER_WEBCORE_CSS_CACHE_COLUMN);
   }
 
+  // Vidmem sorting callback.
+  static gint CompareVidmem(GtkTreeModel* model, GtkTreeIter* a,
+                            GtkTreeIter* b, gpointer task_manager) {
+    return reinterpret_cast<TaskManagerGtk*>(task_manager)->
+        CompareImpl(model, a, b, IDS_TASK_MANAGER_VIDMEM_COLUMN);
+  }
+
   // FPS sorting callback.
   static gint CompareFPS(GtkTreeModel* model, GtkTreeIter* a,
                          GtkTreeIter* b, gpointer task_manager) {