Dont benchmark if the logger has been turned off

git-svn-id: http://svn-commit.rubyonrails.org/rails/trunk@1269 5ecf4fe2-1ee6-0310-87b1-e25e094e27de

actionpack/lib/action_view/helpers/benchmark_helper.rb

@@ -11,6 +11,8 @@ module ActionView
       #
       # Will add something like "Notes section (0.345234)" to the log.
       def benchmark(message = "Benchmarking", &block)
+        return if @logger.nil?
+
         bm = Benchmark.measure do
           block.call
         end