Force GPU switch with CGLSetVirtualScreen only for compositor

content/browser/gpu/gpu_driver_bug_list.json

 // Determines whether a certain driver bug exists in the current system.
 // A valid gpu_driver_bug_list.json file are in the format of
 // {
 //   "version": "x.y",
 //   "entries": [
 //     { // entry 1
 //     },
 //     ...
 //     { // entry n
 //     }
@@ skipping 29 matching lines @@
 // 18. "exceptions" is a list of entries.
 // 19. "features" is a list of driver bug types, including
 //         "clear_alpha_in_readpixels",
 //         "clear_uniforms_before_program_use",
 //         "delete_instead_of_resize_fbo",
 //         "disable_angle_framebuffer_multisample",
 //         "disable_depth_texture",
 //         "disable_ext_occlusion_query",
 //         "enable_chromium_fast_npot_mo8_textures",
 //         "exit_on_context_lost",
+//         "force_cgl_set_virtual_screen",
 //         "flush_on_context_switch",
 //         "max_cube_map_texture_size_limit_1024",
 //         "max_cube_map_texture_size_limit_4096",
 //         "max_cube_map_texture_size_limit_512",
 //         "max_texture_size_limit_4096",
 //         "needs_glsl_built_in_function_emulation",
 //         "needs_offscreen_buffer_workaround",
 //         "restore_scissor_on_fbo_change",
 //         "reverse_point_sprite_coord_origin",
 //         "set_texture_filter_before_generating_mipmap",
@@ skipping 24 matching lines @@
 //
 // FLOAT includes "op" "value", and "value2".  "op" can be any of the
 // following values: "=", "<", "<=", ">", ">=", "any", "between".  "value2" is
 // only used if "op" is "between".  "value" is used for all "op" values except
 // "any". "value" and "value2" are valid float numbers.
 // INT is very much like FLOAT, except that the values need to be integers.
 
 {
   "name": "gpu driver bug list",
   // Please update the version number whenever you change this file.
-  "version": "1.2",
+  "version": "1.3",
   "entries": [
     {
       "id": 1,
       "description": "Imagination driver doesn't like uploading lots of buffer data constantly",
       "os": {
         "type": "android"
       },
       "gl_vendor": {
         "op": "beginwith",
         "value": "Imagination"
@@ skipping 206 matching lines @@
       "id": 18,
       "os": {
         "type": "macosx"
       },
       "vendor_id": "0x10de",
       "device_id": ["0x0fd5"],
       "multi_gpu_category": "any",
       "features": [
         "disable_ext_draw_buffers"
       ]
+    },
+    {
+      "id": 18,

[greggman, 2013/04/08 17:35:26]

I don't know why these have ids :-(  But shouldn't this be 19?

[ccameron, 2013/04/08 17:44:46]

Oops -- disable_ext_draw_buffers snuck in between the 1st and 2nd versions of
this patch!!

[Zhenyao Mo, 2013/04/08 17:46:16]

IDs are for histograms in blacklist. And yes, duplicate IDs are not OK.  I
should probably dcheck in the code to make sure loading will fail.

+      "description": "Workaround for performance problem using CGLSetVirtualScreen",
+      "os": {
+        "type": "macosx"
+      },
+      "vendor_id": "0x10de",
+      "features": [
+        "force_cgl_set_virtual_screen"
+      ]
     }
   ]
 }