Added support for improvement_direction to relevant values, which is propogated to chartjson.

tools/perf/measurements/rasterize_and_record_micro.py

Index: tools/perf/measurements/rasterize_and_record_micro.py
diff --git a/tools/perf/measurements/rasterize_and_record_micro.py b/tools/perf/measurements/rasterize_and_record_micro.py
index 3523a7bb362b91c7422ad4275f2a2498be640745..317a5d277066846f4841942fecab483f3fa3d178 100644
--- a/tools/perf/measurements/rasterize_and_record_micro.py
+++ b/tools/perf/measurements/rasterize_and_record_micro.py
@@ -7,6 +7,7 @@ import time
 
 from telemetry.core.util import TimeoutException
 from telemetry.page import page_test
+from telemetry.value import improvement_direction
 from telemetry.value import scalar
 
 
@@ -73,24 +74,31 @@ class RasterizeAndRecordMicro(page_test.PageTest):
       picture_memory_usage = 0
 
     results.AddValue(scalar.ScalarValue(
-        results.current_page, 'pixels_recorded', 'pixels', pixels_recorded))
+        results.current_page, 'pixels_recorded', 'pixels', pixels_recorded,
+        improvement_direction=improvement_direction.DOWN))
     results.AddValue(scalar.ScalarValue(
-        results.current_page, 'pixels_rasterized', 'pixels', pixels_rasterized))
+        results.current_page, 'pixels_rasterized', 'pixels', pixels_rasterized,
+        improvement_direction=improvement_direction.DOWN))
     results.AddValue(scalar.ScalarValue(
-        results.current_page, 'rasterize_time', 'ms', rasterize_time))
+        results.current_page, 'rasterize_time', 'ms', rasterize_time,
+        improvement_direction=improvement_direction.DOWN))
     results.AddValue(scalar.ScalarValue(
         results.current_page, 'viewport_picture_size', 'bytes',
-        picture_memory_usage))
+        picture_memory_usage,
+        improvement_direction=improvement_direction.DOWN))
     results.AddValue(scalar.ScalarValue(
-        results.current_page, 'record_time', 'ms', record_time))
+        results.current_page, 'record_time', 'ms', record_time,
+        improvement_direction=improvement_direction.DOWN))
     record_time_sk_null_canvas = data['record_time_sk_null_canvas_ms']
     record_time_painting_disabled = data['record_time_painting_disabled_ms']
     results.AddValue(scalar.ScalarValue(
         results.current_page, 'record_time_sk_null_canvas', 'ms',
-        record_time_sk_null_canvas))
+        record_time_sk_null_canvas,
+        improvement_direction=improvement_direction.DOWN))
     results.AddValue(scalar.ScalarValue(
         results.current_page, 'record_time_painting_disabled', 'ms',
-        record_time_painting_disabled))
+        record_time_painting_disabled,
+        improvement_direction=improvement_direction.DOWN))
 
     if self._report_detailed_results:
       pixels_rasterized_with_non_solid_color = \
@@ -112,21 +120,28 @@ class RasterizeAndRecordMicro(page_test.PageTest):
 
       results.AddValue(scalar.ScalarValue(
           results.current_page, 'total_size_of_pictures_in_piles', 'bytes',
-          total_pictures_in_pile_size))
+          total_pictures_in_pile_size,
+          improvement_direction=improvement_direction.DOWN))
       results.AddValue(scalar.ScalarValue(
           results.current_page, 'pixels_rasterized_with_non_solid_color',
-          'pixels', pixels_rasterized_with_non_solid_color))
+          'pixels', pixels_rasterized_with_non_solid_color,
+          improvement_direction=improvement_direction.DOWN))
       results.AddValue(scalar.ScalarValue(
           results.current_page, 'pixels_rasterized_as_opaque', 'pixels',
-          pixels_rasterized_as_opaque))
+          pixels_rasterized_as_opaque,
+          improvement_direction=improvement_direction.DOWN))
       results.AddValue(scalar.ScalarValue(
-          results.current_page, 'total_layers', 'count', total_layers))
+          results.current_page, 'total_layers', 'count', total_layers,
+          improvement_direction=improvement_direction.DOWN))
       results.AddValue(scalar.ScalarValue(
           results.current_page, 'total_picture_layers', 'count',
-          total_picture_layers))
+          total_picture_layers,
+          improvement_direction=improvement_direction.DOWN))
       results.AddValue(scalar.ScalarValue(
           results.current_page, 'total_picture_layers_with_no_content', 'count',
-          total_picture_layers_with_no_content))
+          total_picture_layers_with_no_content,
+          improvement_direction=improvement_direction.DOWN))
       results.AddValue(scalar.ScalarValue(
           results.current_page, 'total_picture_layers_off_screen', 'count',
-          total_picture_layers_off_screen))
+          total_picture_layers_off_screen,
+          improvement_direction=improvement_direction.DOWN))