add firefox extension template

externs/webextension_polyfill/geckoprofiler/Static.hx

@@ -0,0 +1,47 @@
+package webextension_polyfill.geckoprofiler;
+
+typedef Static = {
+	/**
+		Starts the profiler with the specified settings.
+	**/
+	function start(settings:StartSettingsType):Void;
+	/**
+		Stops the profiler and discards any captured profile data.
+	**/
+	function stop():Void;
+	/**
+		Pauses the profiler, keeping any profile data that is already written.
+	**/
+	function pause():Void;
+	/**
+		Resumes the profiler with the settings that were initially used to start it.
+	**/
+	function resume():Void;
+	/**
+		Gathers the profile data from the current profiling session, and writes it to disk.
+		The returned promise resolves to a path that locates the created file.
+	**/
+	function dumpProfileToFile(fileName:String):Void;
+	/**
+		Gathers the profile data from the current profiling session.
+	**/
+	function getProfile():Void;
+	/**
+		Gathers the profile data from the current profiling session. The returned promise resolves to an array buffer that
+		contains a JSON string.
+	**/
+	function getProfileAsArrayBuffer():Void;
+	/**
+		Gathers the profile data from the current profiling session. The returned promise resolves to an array buffer that
+		contains a gzipped JSON string.
+	**/
+	function getProfileAsGzippedArrayBuffer():Void;
+	/**
+		Gets the debug symbols for a particular library.
+	**/
+	function getSymbols(debugName:String, breakpadId:String):Void;
+	/**
+		Fires when the profiler starts/stops running.
+	**/
+	var onRunning : webextension_polyfill.events.Event<(isRunning:Bool) -> Void>;
+};