Revert "[Lacros] Size dashboard: Track stripped size of ELF files."

This reverts commit a4d34d8a.

Reason for revert: This causes chromeos-amd64-generic-lacros-builder-perf to fail, likely due to missing eu-strip.

Original change's description:
> [Lacros] Size dashboard: Track stripped size of ELF files.
>
> This CL modifies lacros_resource_sizes.py to identify ELF files, and
> also track their stripped sizes (using eu-strip) as well as compressed
> stripped sizes. These news info are recorded for chrome and the Total.
>
> If eu-strip fails for a file then we simply ignore its stripping
> results and print warning. Known-bad files include .nexe files and
> libwidevinecdm.so. These are explicitly excluded to denoise the system.
>
> Bug: 1106626
> Change-Id: I9cb47bb41baa2b73996e6662db2fe4bc537338d7
> Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2458869
> Commit-Queue: Samuel Huang <huangs@chromium.org>
> Reviewed-by: Erik Chen <erikchen@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#814972}

TBR=huangs@chromium.org,erikchen@chromium.org

Change-Id: I580c4ea4a125fef785cdb0c6de1c31846a7e8180
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Bug: 1106626
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2459794Reviewed-by: Samuel Huang <huangs@chromium.org>
Commit-Queue: Samuel Huang <huangs@chromium.org>
Cr-Commit-Position: refs/heads/master@{#814986}

build/lacros/lacros_resource_sizes.py

@@ -8,14 +8,12 @@ More information at //docs/speed/binary_size/metrics.md.
 """
 
 import argparse
-import collections
 import contextlib
 import json
 import logging
 import os
 import subprocess
 import sys
-import tempfile
 
 
 @contextlib.contextmanager
@@ -43,9 +41,6 @@ BUILD_COMMON_PATH = os.path.join(DIR_SOURCE_ROOT, 'build', 'util', 'lib',
 TRACING_PATH = os.path.join(DIR_SOURCE_ROOT, 'third_party', 'catapult',
                             'tracing')
 
-EU_STRIP_PATH = os.path.join(DIR_SOURCE_ROOT, 'buildtools', 'third_party',
-                             'eu-strip', 'bin', 'eu-strip')
-
 with _SysPath(BUILD_COMMON_PATH):
   import perf_tests_results_helper  # pylint: disable=import-error
 
@@ -60,11 +55,6 @@ _BASE_CHART = {
     'charts': {}
 }
 
-_KEY_RAW = 'raw'
-_KEY_GZIPPED = 'gzipped'
-_KEY_STRIPPED = 'stripped'
-_KEY_STRIPPED_GZIPPED = 'stripped_then_gzipped'
-
 
 class _Group:
   """A group of build artifacts whose file sizes are summed and tracked.
@@ -77,15 +67,12 @@ class _Group:
   Attributes:
     paths: A list of files or directories to be tracked together.
     title: The display name of the group.
-    track_stripped: Whether to also track summed stripped ELF sizes.
     track_compressed: Whether to also track summed compressed sizes.
   """
 
-  def __init__(self, paths, title, track_stripped=False,
-               track_compressed=False):
+  def __init__(self, paths, title, track_compressed=False):
     self.paths = paths
     self.title = title
-    self.track_stripped = track_stripped
     self.track_compressed = track_compressed
 
 
@@ -94,10 +81,7 @@ class _Group:
 # //infra/config/subprojects/chromium/ci.star) and
 # chromeos-amd64-generic-lacros-internal builder (specified in src-internal).
 _TRACKED_GROUPS = [
-    _Group(paths=['chrome'],
-           title='File: chrome',
-           track_stripped=True,
-           track_compressed=True),
+    _Group(paths=['chrome'], title='File: chrome', track_compressed=True),
     _Group(paths=['crashpad_handler'], title='File: crashpad_handler'),
     _Group(paths=['icudtl.dat'], title='File: icudtl.dat'),
     _Group(paths=['nacl_helper'], title='File: nacl_helper'),
@@ -136,17 +120,6 @@ def _visit_paths(base_dir, paths):
       logging.critical('Not found: %s', path)
 
 
-def _is_probably_elf(filename):
-  """Heuristically decides whether |filename| is ELF via magic signature."""
-  with open(filename, 'rb') as fh:
-    return fh.read(4) == '\x7FELF'
-
-
-def _is_unstrippable_elf(filename):
-  """Identifies known-unstrippable ELF files to denoise the system."""
-  return filename.endswith('.nexe') or filename.endswith('libwidevinecdm.so')
-
-
 def _get_filesize(filename):
   """Returns the size of a file, or 0 if file is not found."""
   try:
@@ -179,37 +152,6 @@ def _get_gzipped_filesize(filename):
   return 0
 
 
-def _get_catagorized_filesizes(filename):
-  """Measures |filename| sizes under various transforms.
-
-  Returns: A Counter (keyed by _Key_* constants) that stores measured sizes.
-  """
-  sizes = collections.Counter()
-  sizes[_KEY_RAW] = _get_filesize(filename)
-  sizes[_KEY_GZIPPED] = _get_gzipped_filesize(filename)
-
-  # Pre-assign values for non-ELF, or in case of failure for ELF.
-  sizes[_KEY_STRIPPED] = sizes[_KEY_RAW]
-  sizes[_KEY_STRIPPED_GZIPPED] = sizes[_KEY_GZIPPED]
-
-  if _is_probably_elf(filename) and not _is_unstrippable_elf(filename):
-    try:
-      fd, temp_file = tempfile.mkstemp()
-      os.close(fd)
-      cmd = [EU_STRIP_PATH, filename, '-o', temp_file]
-      subprocess.check_output(cmd)
-      sizes[_KEY_STRIPPED] = _get_filesize(temp_file)
-      sizes[_KEY_STRIPPED_GZIPPED] = _get_gzipped_filesize(temp_file)
-      if sizes[_KEY_STRIPPED] > sizes[_KEY_RAW]:
-        # This weird case has been observed for libwidevinecdm.so.
-        logging.critical('Stripping made things worse for %s' % filename)
-    except subprocess.CalledProcessError:
-      logging.critical('Failed to strip file: %s' % filename)
-    finally:
-      os.unlink(temp_file)
-  return sizes
-
-
 def _dump_chart_json(output_dir, chartjson):
   """Writes chart histogram to JSON files.
 
@@ -247,49 +189,41 @@ def _run_resource_sizes(args):
   """Main flow to extract and output size data."""
   chartjson = _BASE_CHART.copy()
   report_func = perf_tests_results_helper.ReportPerfResult
-  total_sizes = collections.Counter()
-
-  def report_sizes(sizes, title, track_stripped, track_compressed):
+  total_size = 0
+  total_gzipped = 0
+  for group in _TRACKED_GROUPS:
+    group_size = sum(map(_get_filesize, _visit_paths(args.out_dir,
+                                                     group.paths)))
+    group_gzipped = sum(
+        map(_get_gzipped_filesize, _visit_paths(args.out_dir, group.paths)))
     report_func(chart_data=chartjson,
-                graph_title=title,
+                graph_title=group.title,
                 trace_title='size',
-                value=sizes[_KEY_RAW],
+                value=group_size,
                 units='bytes')
-
-    if track_stripped:
+    if group.track_compressed:
       report_func(chart_data=chartjson,
-                  graph_title=title + ' (Stripped)',
+                  graph_title=group.title + ' (Gzipped)',
                   trace_title='size',
-                  value=sizes[_KEY_STRIPPED],
+                  value=group_gzipped,
                   units='bytes')
-
-    if track_compressed:
-      report_func(chart_data=chartjson,
-                  graph_title=title + ' (Gzipped)',
-                  trace_title='size',
-                  value=sizes[_KEY_GZIPPED],
-                  units='bytes')
-
-    if track_stripped and track_compressed:
-      report_func(chart_data=chartjson,
-                  graph_title=title + ' (Stripped, Gzipped)',
-                  trace_title='size',
-                  value=sizes[_KEY_STRIPPED_GZIPPED],
-                  units='bytes')
-
-  for g in _TRACKED_GROUPS:
-    sizes = sum(
-        map(_get_catagorized_filesizes, _visit_paths(args.out_dir, g.paths)),
-        collections.Counter())
-    report_sizes(sizes, g.title, g.track_stripped, g.track_compressed)
-
-    # Total compressed size is summed over individual compressed sizes, instead
-    # of concatanating first, then compress everything. This is done for
-    # simplicity. It also gives a conservative size estimate (assuming file
-    # metadata and overheads are negligible).
-    total_sizes += sizes
-
-  report_sizes(total_sizes, 'Total', True, True)
+    total_size += group_size
+    # Summing compressed size of separate groups (instead of concatanating
+    # first) to get a conservative estimate. File metadata and overheads are
+    # assumed to be negligible.
+    total_gzipped += group_gzipped
+
+  report_func(chart_data=chartjson,
+              graph_title='Total',
+              trace_title='size',
+              value=total_size,
+              units='bytes')
+
+  report_func(chart_data=chartjson,
+              graph_title='Total (Gzipped)',
+              trace_title='size',
+              value=total_gzipped,
+              units='bytes')
 
   _dump_chart_json(args.output_dir, chartjson)