Include Brillo's cannonical .clang-format file.

Many Brillo repositories need to share a common .clang-format file to
ensure the same formatting rules. This patch moves the .clang-format
file already in system/core/metricsd to a common location to be shared
by other Brillo repositories.

Bug: 27121653
TEST=symlink from system/update_engine, ran clang-format.

Change-Id: Ie04a5a9cf54b9cc24f180fe3896501db4d883a64

tools/brillo-clang-format

@@ -0,0 +1,37 @@
+#
+# Copyright (C) 2016 The Android Open Source Project
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#      http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+#
+
+### DO NOT COPY THIS FILE TO YOUR PROJECT. ###
+
+#
+# This is the .clang-format file used by all Brillo projects, conforming to the
+# style guide defined by Brillo. To use this file create a *relative* symlink in
+# your project pointing to this file, as this repository is expected to be
+# present in all manifests.
+#
+# See go/brillo-c++-style for details about the style guide.
+#
+
+BasedOnStyle: Google
+AllowShortFunctionsOnASingleLine: Inline
+AllowShortIfStatementsOnASingleLine: false
+AllowShortLoopsOnASingleLine: false
+BinPackArguments: false
+BinPackParameters: false
+CommentPragmas: NOLINT:.*
+DerivePointerAlignment: false
+PointerAlignment: Left
+TabWidth: 2