Merge pull request #18 from rauls5382/varset

Add mechanism for extensions to set variable defaults

internal/driver/commands.go

 	pprofCommands[cmd] = &command{format, post, false, desc, usage}
 }
 
+// SetVariableDefault sets the default value for a pprof
+// variable. This enables extensions to set their own defaults.
+func SetVariableDefault(variable, value string) {
+	if v := pprofVariables[variable]; v != nil {
+		v.value = value
+	}
+}
+
 // PostProcessor is a function that applies post-processing to the report output
 type PostProcessor func(input []byte, output io.Writer, ui plugin.UI) error