Add clang-tidy config.

Change-Id: I371f4c9ac696cad9a726491bb3a7e06f38c4b23e
diff --git a/.clang-tidy b/.clang-tidy
new file mode 100644
index 0000000..b7aebb1
--- /dev/null
+++ b/.clang-tidy
@@ -0,0 +1,4 @@
+Checks: android-cloexec-*,bugprone-*,google-explicit-constructor
+CheckOptions:
+  - key:             bugprone-assert-side-effect.AssertMacros
+    value:           'PERFETTO_DCHECK'