[tools] Add gc-nvp-to-csv.py script.

tools/gc_nvp_common.py

Index: tools/gc_nvp_common.py
diff --git a/tools/gc_nvp_common.py b/tools/gc_nvp_common.py
new file mode 100644
index 0000000000000000000000000000000000000000..7a9ad1c4bc85a6d5059651618283b5df07545068
--- /dev/null
+++ b/tools/gc_nvp_common.py
@@ -0,0 +1,32 @@
+# Copyright 2015 the V8 project authors. All rights reserved.
+# Use of this source code is governed by a BSD-style license that can be
+# found in the LICENSE file.
+
+#
+# Common code for parsing --trace-gc-nvp output.
+#
+
+
+from __future__ import with_statement
+import re
+
+def split_nvp(s):
+  t = {}
+  for (name, value) in re.findall(r"(\w+)=([-\w]+)", s):
+    try:
+      t[name] = float(value)
+    except ValueError:
+      t[name] = value
+
+  return t
+
+
+def parse_gc_trace(input):
+  trace = []
+  with open(input) as f:
+    for line in f:
+      info = split_nvp(line)
+      if info and 'pause' in info and info['pause'] > 0:
+        info['i'] = len(trace)
+        trace.append(info)
+  return trace