runner/size.rb: fix metric passed to output

runner/peak.rb: ditto

This is needed to make commands like `make -C .ruby-svn benchmark
ITEM=erb OPTS="-r size -o simple"` succeed.

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@63932 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

benchmark/lib/benchmark_driver/runner/peak.rb

@@ -40,7 +40,7 @@ class BenchmarkDriver::Runner::Peak
               run_benchmark(job, context: context)
             end
             @output.with_context(name: context.name, executable: context.executable, gems: context.gems, prelude: context.prelude) do
-              @output.report(values: { METRIC => value }, loop_count: job.loop_count)
+              @output.report(values: { metric => value }, loop_count: job.loop_count)
             end
           end
         end
@@ -80,6 +80,11 @@ class BenchmarkDriver::Runner::Peak
     'peak'
   end
 
+  # Overridden by BenchmarkDriver::Runner::Size
+  def metric
+    METRIC
+  end
+
   def with_script(script)
     if @config.verbose >= 2
       sep = '-' * 30

benchmark/lib/benchmark_driver/runner/size.rb

@@ -13,6 +13,11 @@ class BenchmarkDriver::Runner::Size < BenchmarkDriver::Runner::Peak
 
   private
 
+  # Overriding BenchmarkDriver::Runner::Peak#metric
+  def metric
+    METRIC
+  end
+
   # Overriding BenchmarkDriver::Runner::Peak#target
   def target
     'size'