utils: ipc: import mojo

Import mojo from the Chromium repository, so that we can use it for
generating code for the IPC mechanism. The commit from which this was
taken is:
a079161ec8c6907b883f9cb84fc8c4e7896cb1d0 "Add PPAPI constructs for
sending focus object to PdfAccessibilityTree"

This tree has been pruned to remove directories that didn't have any
necessary code:
- mojo/* except for mojo/public
  - mojo core, docs, and misc files
- mojo/public/* except for mojo/public/{tools,LICENSE}
  - language bindings for IPC, tests, and some mojo internals
- mojo/public/tools/{fuzzers,chrome_ipc}
- mojo/public/tools/bindings/generators
  - code generation for other languages

No files were modified.

Signed-off-by: Paul Elder <paul.elder@ideasonboard.com>
Acked-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Acked-by: Niklas Söderlund <niklas.soderlund@ragnatech.se>
Acked-by: Kieran Bingham <kieran.bingham@ideasonboard.com>

utils/ipc/mojo/public/tools/bindings/concatenate-files.py

@@ -0,0 +1,54 @@
+#!/usr/bin/env python
+# Copyright 2019 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.
+#
+# This utility concatenates several files into one. On Unix-like systems
+# it is equivalent to:
+#   cat file1 file2 file3 ...files... > target
+#
+# The reason for writing a separate utility is that 'cat' is not available
+# on all supported build platforms, but Python is, and hence this provides
+# us with an easy and uniform way of doing this on all platforms.
+
+# for py2/py3 compatibility
+from __future__ import print_function
+
+import optparse
+
+
+def Concatenate(filenames):
+  """Concatenate files.
+
+  Args:
+    files: Array of file names.
+           The last name is the target; all earlier ones are sources.
+
+  Returns:
+    True, if the operation was successful.
+  """
+  if len(filenames) < 2:
+    print("An error occurred generating %s:\nNothing to do." % filenames[-1])
+    return False
+
+  try:
+    with open(filenames[-1], "wb") as target:
+      for filename in filenames[:-1]:
+        with open(filename, "rb") as current:
+          target.write(current.read())
+    return True
+  except IOError as e:
+    print("An error occurred when writing %s:\n%s" % (filenames[-1], e))
+    return False
+
+
+def main():
+  parser = optparse.OptionParser()
+  parser.set_usage("""Concatenate several files into one.
+      Equivalent to: cat file1 ... > target.""")
+  (_options, args) = parser.parse_args()
+  exit(0 if Concatenate(args) else 1)
+
+
+if __name__ == "__main__":
+  main()