DevTools: Turn *Model events into symbols

third_party/WebKit/Source/devtools/front_end/sdk/RuntimeModel.js

Index: third_party/WebKit/Source/devtools/front_end/sdk/RuntimeModel.js
diff --git a/third_party/WebKit/Source/devtools/front_end/sdk/RuntimeModel.js b/third_party/WebKit/Source/devtools/front_end/sdk/RuntimeModel.js
index 64592f574ec91d83425ebccd515fab1f1ddecba7..350ba9248e471c0e0a611b032eb7cd48b358ddff 100644
--- a/third_party/WebKit/Source/devtools/front_end/sdk/RuntimeModel.js
+++ b/third_party/WebKit/Source/devtools/front_end/sdk/RuntimeModel.js
@@ -53,10 +53,10 @@ WebInspector.RuntimeModel = function(target)
 
 /** @enum {symbol} */
 WebInspector.RuntimeModel.Events = {
-    ExecutionContextCreated: ("ExecutionContextCreated"),
-    ExecutionContextDestroyed: ("ExecutionContextDestroyed"),
-    ExecutionContextChanged: ("ExecutionContextChanged"),
-    ExecutionContextOrderChanged: ("ExecutionContextOrderChanged")
+    ExecutionContextCreated: Symbol("ExecutionContextCreated"),
+    ExecutionContextDestroyed: Symbol("ExecutionContextDestroyed"),
+    ExecutionContextChanged: Symbol("ExecutionContextChanged"),
+    ExecutionContextOrderChanged: Symbol("ExecutionContextOrderChanged")
 }
 
 WebInspector.RuntimeModel._privateScript = "private script";