Histograms.xml python script housekeeping

tools/metrics/histograms/update_use_counter_feature_enum.py

Index: tools/metrics/histograms/update_use_counter_feature_enum.py
diff --git a/tools/metrics/histograms/update_use_counter_feature_enum.py b/tools/metrics/histograms/update_use_counter_feature_enum.py
index 28a49942768d134ac1b232590fae872b4fdc0bf2..98885dcb4d7d8180ba766492d5930e4f191cbb37 100755
--- a/tools/metrics/histograms/update_use_counter_feature_enum.py
+++ b/tools/metrics/histograms/update_use_counter_feature_enum.py
@@ -13,9 +13,7 @@ import optparse
 import os
 import sys
 
-sys.path.append(os.path.join(os.path.dirname(__file__), '..', 'common'))

[Ilya Sherman, 2015/05/27 00:12:24]

Why is this line no longer needed?  I believe that it was previously added to
allow the script to be run from any directory.

[ncarter (slow), 2015/05/29 23:01:10]

This statement would allow a script in tools/metrics/histogram to use the
"import" keyword to pull in a script from tools/metrics/common as a module. It
works by modifying the import search path. Other files in this directory did
this to pull in diff_util from common. It looks like it was just mistakenly
copied to this file, because no module from common is actually imported here.

In the new patch set I've changed how these scripts handle imports (they adjust
the search path to include 'tools/metrics' and then import relative from there).

-from update_histogram_enum import ReadHistogramValues
-from update_histogram_enum import UpdateHistogramEnum
+import update_histogram_enum
 
 
 def PrintEnumForDashboard(enum_dict):
@@ -33,17 +31,18 @@ if __name__ == '__main__':
                     'https://github.com/GoogleChrome/chromium-dashboard')
   options, args = parser.parse_args()
 
-  source_path = \
-      '../../../third_party/WebKit/Source/core/frame/UseCounter.h'
+  source_path = 'third_party/WebKit/Source/core/frame/UseCounter.h'
 
   START_MARKER = '^enum Feature {'
   END_MARKER = '^NumberOfFeatures'
 
   if options.dashboard:
-    enum_dict = ReadHistogramValues(source_path, START_MARKER, END_MARKER)
+    enum_dict = update_histogram_enum.ReadHistogramValues(source_path,
+                                                          START_MARKER,
+                                                          END_MARKER)
     PrintEnumForDashboard(enum_dict)
   else:
-    UpdateHistogramEnum(
+    update_histogram_enum.UpdateHistogramEnum(
         histogram_enum_name='FeatureObserver',
         source_enum_path=source_path,
         start_marker=START_MARKER,