The C++ style in Minikin follows Android Framework C++ Code Style Guide except for following rules:
In dir/foo.cc or dir/foo_test.cc, whose main purpose is to implement or test the stuff in
dir2/foo2.h, order your includes as follows:
For example,
```
#include "minikin/Layout.h" // The corresponding header file.
#include <math.h> // C system header files.
#include // C++ system header files.
#include <hb.h> // Other library, HarfBuzz, header file.
#include <log/log.h> // Other library, Android, header file.
#include <unicode/ubidi.h> // Other library, ICU, header file.
#include "minikin/Emoji.h" // The minikin public header file.
#include "HbFontCache.h" // The minikin private header file.
```
"<>" vs ""
#include <...>
should be used for non local library files.
#include "..."
should be used for minikin header files.