Revert 175810 - looks like this revert broke some tests.

tools/perf/perf_tools/image_decoding_benchmark.py

 # Copyright (c) 2012 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 import multi_page_benchmark
 
 
 class ImageDecoding(multi_page_benchmark.MultiPageBenchmark):
   def WillNavigateToPage(self, page, tab):
     tab.timeline.Start()
 
   def MeasurePage(self, page, tab, results):
     tab.timeline.Stop()
     def _IsDone():
       return tab.runtime.Evaluate('isDone')
 
     decode_image_events = \
-        tab.timeline.timeline_events.GetAllOfType('DecodeImage')
+        tab.timeline.timeline_events.GetAllOfName('DecodeImage')
 
     # If it is a real image benchmark, then store only the last-minIterations
     # decode tasks.
     if (hasattr(page,
                 'image_decoding_benchmark_limit_results_to_min_iterations') and
         page.image_decoding_benchmark_limit_results_to_min_iterations):
       assert _IsDone()
       min_iterations = tab.runtime.Evaluate('minIterations')
       decode_image_events = decode_image_events[-min_iterations:]
 
-    elapsed_times = [d.elapsed_time for d in decode_image_events]
-    if not elapsed_times:
+    durations = [d.duration_ms for d in decode_image_events]
+    if not durations:
       results.Add('ImageDecoding_avg', 'ms', 'unsupported')
       return
-    image_decoding_avg = sum(elapsed_times) / len(elapsed_times)
+    image_decoding_avg = sum(durations) / len(durations)
     results.Add('ImageDecoding_avg', 'ms', image_decoding_avg)