Revert 192526 "Telemetry: Don't silently compare histograms from..."

trunk/src/tools/perf/perf_tools/histogram.py

Index: trunk/src/tools/perf/perf_tools/histogram.py
===================================================================
--- trunk/src/tools/perf/perf_tools/histogram.py	(revision 192526)
+++ trunk/src/tools/perf/perf_tools/histogram.py	(working copy)
@@ -13,18 +13,12 @@
   if 'buckets' not in start_histogram:
     return histogram_json
 
-  histogram = json.loads(histogram_json)
-  if ('pid' in start_histogram and 'pid' in histogram
-      and start_histogram['pid'] != histogram['pid']):
-    raise Exception(
-        'Trying to compare histograms from different processes (%d and %d)'
-        % (start_histogram['pid'], histogram['pid']))
-
   start_histogram_buckets = dict()
   for b in start_histogram['buckets']:
     start_histogram_buckets[b['low']] = b['count']
 
   new_buckets = []
+  histogram = json.loads(histogram_json)
   for b in histogram['buckets']:
     new_bucket = b
     low = b['low']