Use GPU blacklist to control accelerated video decode.

chrome/browser/resources/software_rendering_list.json

 // Determines whether certain gpu-related features are blacklisted or not.
 // A valid software_rendering_list.json file are in the format of
 // {
 //   "version": "x.y",
 //   "entries": [
 //     { // entry 1
 //     },
 //     ...
 //     { // entry n
 //     }
@@ skipping 19 matching lines @@
 //    The version is interpreted as "year.month.day".
 // 10. "gl_vendor" is a STRING structure (defined below).
 // 11. "gl_renderer" is a STRING structure (defined below).
 // 12. "perf_graphics" is a FLOAT structure (defined below).
 // 13. "perf_gaming" is a FLOAT structure (defined below).
 // 14. "perf_overall" is a FLOAT structure (defined below).
 // 15. "exceptions" is a list of entries.
 // 16. "blacklist" is a list of gpu feature strings, valid values include
 //     "accelerated_2d_canvas", "accelerated_compositing", "webgl",
 //     "multisampling", "flash_3d", "flash_stage3d", "texture_sharing",
-//     and "all".
+//     "accelerated_video_decode", and "all".
 //     This field is mandatory.
 // 17. "description" has the description of the entry.
 // 18. "webkit_bugs" is an array of associated webkit bug numbers.
 // 19. "cr_bugs" is an array of associated webkit bug numbers.
 // 20. "browser_version" is a VERSION structure (defined below).  If this
 //     condition is not satisfied, the entry will be ignored.  If it is not
 //     present, then the entry applies to all versions of the browser.
 // 21. "disabled" is a boolean. If it is present, the entry will be skipped.
 //     This can not be used in exceptions.
 //
@@ skipping 10 matching lines @@
 // "contains", "beginwith", "endwith", "=".  "value" is a string.
 //
 // 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.
 
 {
   "name": "software rendering list",
   // Please update the version number whenever you change this file.
-  "version": "2.8",
+  "version": "2.9",
   "entries": [
     {
       "id": 1,
       "description": "ATI Radeon X1900 is not compatible with WebGL on the Mac.",
       "webkit_bugs": [47028],
       "os": {
         "type": "macosx"
       },
       "vendor_id": "0x1002",
       "device_id": ["0x7249"],
@@ skipping 576 matching lines @@
         "op": "=",
         "value": "NVIDIA"
       },
       "driver_version": {
         "op": "<",
         "number": "295"
       },
       "blacklist": [
         "all"
       ]
+    },
+    {
+      "id": 48,
+      "description": "Accelerated video decode is unavailable on Mac and Linux.",
+      "cr_bugs": [137247, 142402],

[Ami GONE FROM CHROMIUM, 2012/08/17 17:51:03]

s/142402/133828/
(the former is now resolved, the latter is the mac tracking bug)

[Zhenyao Mo, 2012/08/17 20:08:17]

Done.

+      "exceptions": [
+        {
+          "os": {
+            "type": "chromeos"
+          }
+        },
+        {
+          "os": {
+            "type": "win"

[Ami GONE FROM CHROMIUM, 2012/08/17 17:51:03]

FYI this is compatible w/ ToT now that I reverted the disablement in 152086.

+          }
+        }
+      ],
+      "blacklist": [
+        "accelerated_video_decode"
+      ]
     }
   ]
 }