Added UMA stats for extensions events on addListener.

tools/json_schema_compiler/schema_util.py

Index: tools/json_schema_compiler/schema_util.py
diff --git a/tools/json_schema_compiler/schema_util.py b/tools/json_schema_compiler/schema_util.py
index 7ce399e8ed31e0a0a75a76d82176a39a9a00e6a1..be3d0df6a525645969472e202e65e8a46087e297 100644
--- a/tools/json_schema_compiler/schema_util.py
+++ b/tools/json_schema_compiler/schema_util.py
@@ -23,6 +23,16 @@ def SplitNamespace(ref):
     return tuple(ref.rsplit('.', 1))
   return (None, ref)
 
+def JsEventNameToHistogramValue(namespace_name, event_name):
+  """Transform a fully qualified event name like foo.bar.baz into FOO_BAR_BAZ
+
+  Format based on
+  chrome/browser/extensions/extension_event_histogram_value.h .
+
+  DOES NOT strip any leading 'experimental' prefix."""
+  full_name = namespace_name + "." + event_name
+  return full_name.upper().replace(".", "_")
+
 def JsFunctionNameToClassName(namespace_name, function_name):
   """Transform a fully qualified function name like foo.bar.baz into FooBarBaz