supersize: Don't cluster by default. Make Diff() accept only SizeInfo.

tools/binary_size/libsupersize/describe.py

 # Copyright 2017 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.
 """Methods for converting model objects to human-readable formats."""
 
 import datetime
 import itertools
 import time
 
 import models
@@ skipping 202 matching lines @@
       return self._DescribeSymbolDiff(obj)
     if isinstance(obj, models.SymbolGroup):
       return self._DescribeSymbolGroup(obj)
     if isinstance(obj, models.Symbol):
       return self._DescribeSymbol(obj)
     return (repr(obj),)
 
 
 def DescribeSizeInfoCoverage(size_info):
   """Yields lines describing how accurate |size_info| is."""
-  symbols = models.SymbolGroup(size_info.raw_symbols)
   for section in models.SECTION_TO_SECTION_NAME:
     if section == 'd':
       expected_size = sum(v for k, v in size_info.section_sizes.iteritems()
                           if k.startswith('.data'))
     else:
       expected_size = size_info.section_sizes[
           models.SECTION_TO_SECTION_NAME[section]]
 
     def one_stat(group):
       template = ('Section {}: has {:.1%} of {} bytes accounted for from '
                   '{} symbols. {} bytes are unaccounted for.')
       actual_size = group.size
       size_percent = float(actual_size) / expected_size
       return template.format(section, size_percent, actual_size, len(group),
                              expected_size - actual_size)
 
-    in_section = symbols.WhereInSection(section)
+    in_section = size_info.symbols.WhereInSection(section)
     yield one_stat(in_section)
     yield '* Padding accounts for {} bytes ({:.1%})'.format(
         in_section.padding, float(in_section.padding) / in_section.size)
 
     aliased_symbols = in_section.Filter(lambda s: s.aliases)
     if len(aliased_symbols):
       uniques = sum(1 for s in aliased_symbols.IterUniqueSymbols())
       yield '* Contains {} aliases, mapped to {} addresses ({} bytes)'.format(
           len(aliased_symbols), uniques, aliased_symbols.size)
     else:
@@ skipping 41 matching lines @@
 
 def GenerateLines(obj, verbose=False, recursive=False):
   """Returns an iterable of lines (without \n) that describes |obj|."""
   return Describer(verbose=verbose, recursive=recursive).GenerateLines(obj)
 
 
 def WriteLines(lines, func):
   for l in lines:
     func(l)
     func('\n')