Fix the units for the draw_properties benchmark.

tools/perf/measurements/draw_properties.py

 # Copyright 2015 The Chromium Authors. All rights reserved.
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
 from telemetry.core.platform import tracing_category_filter
 from telemetry.core.platform import tracing_options
 from telemetry.page import page_test
 from telemetry.timeline import model
 from telemetry.value import scalar
 
@@ skipping 33 matching lines @@
         timeline_model,
         "LayerTreeHostCommon::CalculateDrawProperties");
 
     (pt_avg, pt_sum) = self.ComputeAverageAndSumOfDurations(
         timeline_model,
         "LayerTreeHostCommon::ComputeVisibleRectsWithPropertyTrees");
 
     reduction = 100.0 * (1.0 - (pt_sum / cdp_sum))
 
     results.AddValue(scalar.ScalarValue(
-        results.current_page, 'CDP_reduction', ' %', reduction,
+        results.current_page, 'CDP_reduction', 'reduction%', reduction,
         description='Reduction in CDP cost with property trees'))
 
     results.AddValue(scalar.ScalarValue(
         results.current_page, 'CDP_avg_cost', 'ms', cdp_avg,
         description='Average time spent in CDP'))
 
     results.AddValue(scalar.ScalarValue(
         results.current_page, 'PT_avg_cost', 'ms', pt_avg,
         description='Average time spent processing property trees'))
 
   def CleanUpAfterPage(self, page, tab):
     tracing_controller = tab.browser.platform.tracing_controller
     if tracing_controller.is_tracing_running:
       tracing_controller.Stop()