Merge to XFA: Add a .clang-format config file.

This is the .clang-format file I used to format everything.

BUG=none
R=tsepez@chromium.org

Review URL: https://codereview.chromium.org/1260183009 .
diff --git a/.clang-format b/.clang-format
new file mode 100644
index 0000000..2fb833a
--- /dev/null
+++ b/.clang-format
@@ -0,0 +1,2 @@
+# http://clang.llvm.org/docs/ClangFormatStyleOptions.html
+BasedOnStyle: Chromium