Fixed ruby-prof changes and let's use latest ruby-prof now.

Gemfile

@@ -50,7 +50,7 @@ instance_eval File.read local_gemfile if File.exists? local_gemfile
 
 platforms :mri do
   group :test do
-    gem 'ruby-prof', '0.10.8'
+    gem 'ruby-prof', '~> 0.11.2'
   end
 end
 

activesupport/lib/active_support/testing/performance/ruby.rb

@@ -36,7 +36,7 @@ module ActiveSupport
           RubyProf.pause
           full_profile_options[:runs].to_i.times { run_test(@metric, :profile) }
           @data = RubyProf.stop
-          @total = @data.threads.values.sum(0) { |method_infos| method_infos.max.total_time }
+          @total = @data.threads.sum(0) { |thread| thread.methods.max.total_time }
         end
 
         def record