Add Tracing.getCategories to protocol.json.

Source/devtools/protocol.json

Index: Source/devtools/protocol.json
diff --git a/Source/devtools/protocol.json b/Source/devtools/protocol.json
index efb1b5ad5f256922ea642233e8eccae62efe40ec..885ea68b1d861c796ca29ab948fd1535749b150d 100644
--- a/Source/devtools/protocol.json
+++ b/Source/devtools/protocol.json
@@ -4126,6 +4126,19 @@
                 "name": "end",
                 "description": "Stop trace events collection.",
                 "handlers": ["browser", "frontend"]
+            },
+            {
+                "name": "getCategories",
+                "description": "Gets supported tracing categories.",
+                "returns": [
+                    {
+                        "name": "categories",

[pfeldman, 2014/06/18 03:35:00]

nit: we use line-per parameter code style here.

[chrishenry, 2014/06/18 16:55:43]

Done.

+                        "type": "array",
+                        "items": { "type": "string" },
+                        "description": "A list of supported tracing categories."
+                    }
+                ],
+                "handlers": ["browser", "frontend"]
             }
         ],
         "events": [