Add Bloaty (with demangling) for wasm BuildStats

The bloaty here was compiled with this patch:
https://github.com/google/bloaty/pull/149

Hopefully that lands upstream and we can track master again.

This adds BuildStats.+Debug because we need symbols
to get sensical data. Bloaty's WASM support is experimental
and currently doesn't support having a stripped (Release)
version be profiled using the symbols of a Debug version.

This means that the buildStats for debug will be higher
than actual, but hopefully the absolute positioning will be
the same and thus the outputs useful.

Bug: skia:
Change-Id: Id7bf721843e8c52a0aae2b7e57ff95397693b3dd
Reviewed-on: https://skia-review.googlesource.com/c/163256
Reviewed-by: Mike Klein <mtklein@google.com>
Commit-Queue: Kevin Lubick <kjlubick@google.com>
diff --git a/infra/bots/buildstats/buildstats_wasm.py b/infra/bots/buildstats/buildstats_wasm.py
new file mode 100644
index 0000000..4e24fac
--- /dev/null
+++ b/infra/bots/buildstats/buildstats_wasm.py
@@ -0,0 +1,79 @@
+# Copyright 2018 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.
+
+
+"""Writes a Perf-formated json file with stats about the given web file."""
+
+
+import json
+import os
+import subprocess
+import sys
+
+
+def main():
+  input_file = sys.argv[1]
+  out_dir = sys.argv[2]
+  keystr = sys.argv[3]
+  propstr = sys.argv[4]
+  bloaty_path = sys.argv[5]
+
+  results = {
+    'key': { },
+    'results': { }
+  }
+
+  magic_seperator = '#$%^&*'
+  print magic_seperator
+  print 'If you see lots of func[19] and such, go check out the debug build'
+  print ('Note that template instantiations are grouped together, '
+         'thus the elided types.')
+  print ('If you notice an unsymbolized "duplicate" entry, it is simply how '
+         'many bytes the function name itself takes up')
+  print subprocess.check_output([bloaty_path, input_file,
+                                 '-d', 'shortsymbols', '-n', '0'])
+
+  print magic_seperator
+  print 'If you see lots of func[19] and such, go check out the debug build'
+  print subprocess.check_output([bloaty_path, input_file,
+                                 '-d', 'fullsymbols', '-n', '0'])
+
+  props = propstr.split(' ')
+  for i in range(0, len(props), 2):
+    results[props[i]] = props[i+1]
+
+  keys = keystr.split(' ')
+  for i in range(0, len(keys), 2):
+    results['key'][keys[i]] = keys[i+1]
+
+  r = {
+    'total_size_bytes': os.path.getsize(input_file)
+  }
+
+  # Make a copy to avoid destroying the hardlinked file.
+  # Swarming hardlinks in the builds from isolated cache.
+  temp_file = input_file + '_tmp'
+  subprocess.check_call(['cp', input_file, temp_file])
+  subprocess.check_call(['gzip', temp_file])
+
+  r['gzip_size_bytes'] = os.path.getsize(temp_file + '.gz')
+
+  name = os.path.basename(input_file)
+
+  results['results'][name] = {
+    # We need this top level layer 'config'/slice
+    # Other analysis methods (e.g. libskia) might have
+    # slices for data on the 'code' section, etc.
+    'default' : r,
+  }
+
+  print magic_seperator
+  print json.dumps(results, indent=2)
+
+  with open(os.path.join(out_dir, name+'.json'), 'w') as output:
+    output.write(json.dumps(results, indent=2))
+
+
+if '__main__' == __name__:
+  main()