New misc scripts, header_usage.sh and author_line_count.sh.

NOTRY=True
BUG=

Review-Url: https://codereview.webrtc.org/2061683002
Cr-Commit-Position: refs/heads/master@{#13148}
diff --git a/webrtc/tools/header_usage.sh b/webrtc/tools/header_usage.sh
new file mode 100755
index 0000000..6bb8901
--- /dev/null
+++ b/webrtc/tools/header_usage.sh
@@ -0,0 +1,23 @@
+#!/bin/bash
+
+# Copyright (c) 2016 The WebRTC 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 in the root of the source
+# tree. An additional intellectual property rights grant can be found
+# in the file PATENTS.  All contributing project authors may
+# be found in the AUTHORS file in the root of the source tree.
+
+# This script is run in a git repository. It lists all header files,
+# sorted by the number of other files where the file name of the file
+# occurs. It is intentionally not limited to only source files, and
+# there may be some false hits because we search only for the file
+# part (sans directory). It is quite slow.
+#
+# Headers close to the top of the list are candidates for removal.
+
+git ls-files '*.h' '*.hpp' | while read header ; do
+  name="$(basename "${header}")"
+  count="$(git grep -l -F  "${name}" | wc -l)"
+  echo "${count}" "${header}"
+done | sort -n