Re-enable GPU features except accelerated 2d canvas for GeForce 9400M on Mac.

gpu/software_rendering_list/software_rendering_list.json

Index: gpu/software_rendering_list/software_rendering_list.json
===================================================================
--- gpu/software_rendering_list/software_rendering_list.json	(revision 141304)
+++ gpu/software_rendering_list/software_rendering_list.json	(working copy)
@@ -65,7 +65,7 @@
 {
   "name": "software rendering list",
   // Please update the version number whenever you change this file.
-  "version": "1.38",
+  "version": "1.39",
   "entries": [
     {
       "id": 1,
@@ -574,15 +574,19 @@
     },
     {
       "id": 38,
-      "description": "NVidia GeForce 9400M is buggy on Mac.",
+      "description": "Accelerated 2D canvas is unstable for NVidia GeForce 9400M on Lion.",
       "cr_bugs": [130495],
       "os": {
-        "type": "macosx"
+        "type": "macosx",
+        "version": {
+          "op": "=",
+          "number": "10.7"
+        }
       },
       "vendor_id": "0x10de",
       "device_id": ["0x0863"],
       "blacklist": [
-        "all"
+        "accelerated_2d_canvas"
       ]
     }
   ]