Add most of base/ build/ buildtools/ testing/ third_party/googletest/

Enough to make ./tools/gn/bootstrap/bootstrap.py work on Linux.

Change-Id: I94de95f1ce87dd3672d1a99c62254edee8be45bd
Reviewed-on: https://gn-review.googlesource.com/1100
Reviewed-by: Petr Hosek <phosek@google.com>
Commit-Queue: Scott Graham <scottmg@chromium.org>
diff --git a/buildtools/codereview.settings b/buildtools/codereview.settings
new file mode 100644
index 0000000..ac1510a
--- /dev/null
+++ b/buildtools/codereview.settings
@@ -0,0 +1,4 @@
+# This file is used by git-cl to get repository specific information.
+GERRIT_HOST: True
+CODE_REVIEW_SERVER: codereview.chromium.org
+PROJECT: buildtools