Adding documentation for "style" in version in software rendering list.

gpu/software_rendering_list/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 27 matching lines @@
 //     This field is mandatory.
 // 16. "description" has the description of the entry.
 // 17. "webkit_bugs" is an array of associated webkit bug numbers.
 // 18. "cr_bugs" is an array of associated webkit bug numbers.
 // 19. "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.
 // 20. "disabled" is a boolean. If it is present, the entry will be skipped.
 //     This can not be used in exceptions.
 //
-// VERSION includes "op" "number", and "number2".  "op" can be any of the
-// following values: "=", "<", "<=", ">", ">=", "any", "between".  "number2" is
-// only used if "op" is "between".  "number" is used for all "op" values except
-// "any". "number" and "number2" are in the format of x, x.x, x.x.x, etc.
+// VERSION includes "op", "style", "number", and "number2".  "op" can be any of
+// the following values: "=", "<", "<=", ">", ">=", "any", "between".  "style"
+// is optional and can be "lexical" or "numerical"; if it's not specified, it
+// defaults to "numerical".  "number2" is only used if "op" is "between".
+// "number" is used for all "op" values except "any". "number" and "number2"
+// are in the format of x, x.x, x.x.x, etc.
+// Only "driver_version" supports lexical style if the format is major.minor;
+// in that case, major is still numerical, but minor is lexical. 
 //
 // STRING includes "op" and "value".  "op" can be any of the following values:
 // "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.
 
 {
@@ skipping 514 matching lines @@
         "type": "macosx"
       },
       "vendor_id": "0x10de",
       "device_id": ["0x0863"],
       "blacklist": [
         "all"
       ]
     }
   ]
 }