[telemetry] Sort imports in Telemetry and its dependents.

tools/perf/metrics/memory.py

 # Copyright 2013 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.
 
 import sys
 
-from metrics import Metric
 from telemetry.value import histogram
 from telemetry.value import histogram_util
 from telemetry.value import scalar
 
+from metrics import Metric
+
 
 _HISTOGRAMS = [
     {
         'name': 'V8.MemoryExternalFragmentationTotal', 'units': 'percent',
         'display_name': 'V8_MemoryExternalFragmentationTotal',
         'type': histogram_util.RENDERER_HISTOGRAM,
         'description': 'Total external memory fragmentation after each GC in '
                        'percent.',
     },
     {
@@ skipping 201 matching lines @@
     AddResult('VMPeak', 'vm_peak_size',
               'The peak Virtual Memory Size (address space allocated) usage '
               'achieved by the * process.')
     AddResult('WorkingSetSizePeak', '%s_peak_size' % metric,
               'Peak Working Set Size.')
 
   AddResultsForProcessTypes(['Browser'], 'browser')
   AddResultsForProcessTypes(['Renderer'], 'renderer')
   AddResultsForProcessTypes(['Gpu'], 'gpu')
   AddResultsForProcessTypes(['Browser', 'Renderer', 'Gpu'], 'total')