supersize: Fix path counts, missing section in clusters

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 182 matching lines @@
     children_desc = self._DescribeSymbolGroupChildren(group)
     return itertools.chain(header_desc, children_desc)
 
   def _DescribeDiffObjectPaths(self, diff):
     paths_by_status = [set(), set(), set(), set()]
     def helper(group):
       for s in group:
         if s.IsGroup():
           helper(s)
         else:
-          status = group.DiffStatus(s)
-          paths_by_status[status].add(s.source_path or s.object_path)
+          path = s.source_path or s.object_path
+          # Ignore paths like foo/{shared}/2
+          if '{' not in path:
+            paths_by_status[group.DiffStatus(s)].add(path)
     helper(diff)
-    # Show only paths that have no changed symbols (pure adds / removes).
+    # Initial paths sets are those where *any* symbol is
+    # unchanged/changed/added/removed.
     unchanged, changed, added, removed = paths_by_status
+    # Consider a path with both adds & removes as "changed".
+    changed.update(added.intersection(removed))
+    # Consider a path added / removed only when all symbols are new/removed.
     added.difference_update(unchanged)
     added.difference_update(changed)
+    added.difference_update(removed)
     removed.difference_update(unchanged)
     removed.difference_update(changed)
+    removed.difference_update(added)
     yield '{} paths added, {} removed, {} changed'.format(
         len(added), len(removed), len(changed))
 
     if self.verbose and len(added):
       yield 'Added files:'
       for p in sorted(added):
         yield '  ' + p
     if self.verbose and len(removed):
       yield 'Removed files:'
       for p in sorted(removed):
@@ skipping 135 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')