Cherry-pick m45 fixes onto m44

tools/llvm_coverage_run.py

Index: tools/llvm_coverage_run.py
diff --git a/tools/llvm_coverage_run.py b/tools/llvm_coverage_run.py
new file mode 100755
index 0000000000000000000000000000000000000000..8b497506e64d3dfb59911f98d28a66bb3c2fe84c
--- /dev/null
+++ b/tools/llvm_coverage_run.py
@@ -0,0 +1,63 @@
+#!/usr/bin/env python
+# Copyright (c) 2015 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.
+
+
+"""Run the given command through LLVM's coverage tools."""
+
+
+import argparse
+import os
+import subprocess
+
+
+BUILDTYPE = 'Coverage'
+PROFILE_DATA = 'default.profraw'
+PROFILE_DATA_MERGED = 'prof_merged'
+SKIA_OUT = 'SKIA_OUT'
+
+
+def _get_out_dir():
+  """Determine the location for compiled binaries."""
+  return os.path.join(os.environ.get(SKIA_OUT, os.path.realpath('out')),
+                      BUILDTYPE)
+
+
+def run_coverage(cmd):
+  """Run the given command and return per-file coverage data.
+
+  Assumes that the binary has been built using llvm_coverage_build and that
+  LLVM 3.6 or newer is installed.
+  """
+  binary_path = os.path.join(_get_out_dir(), cmd[0])
+  subprocess.call([binary_path] + cmd[1:])
+  try:
+    subprocess.check_call(
+        ['llvm-profdata', 'merge', PROFILE_DATA,
+         '-output=%s' % PROFILE_DATA_MERGED])
+  finally:
+    os.remove(PROFILE_DATA)
+  try:
+    return subprocess.check_output(['llvm-cov', 'show', '-no-colors',
+                                    '-instr-profile', PROFILE_DATA_MERGED,
+                                    binary_path])
+  finally:
+    os.remove(PROFILE_DATA_MERGED)
+
+
+def main():
+  """Run coverage and generate a report."""
+  # Parse args.
+  parser = argparse.ArgumentParser()
+  parser.add_argument('--outResultsFile')
+  args, cmd = parser.parse_known_args()
+
+  # Run coverage.
+  report = run_coverage(cmd)
+  with open(args.outResultsFile, 'w') as f:
+    f.write(report)
+
+
+if __name__ == '__main__':
+  main()