android: Define OS_CHROMEOS macro if android_platform=cros

Android Camera HAL 3 API used in ChromeOS has a ChromeOS own
extension, for example, crop_rotate_scale_degrees in
camera3_stream. As those extensions are not available on Android
platforms, introduce a OS_CHROMEOS macro that can be used to
compile CrOS-specific code conditionally. The macro is defined
if and only if android_platform is 'cros'.

Signed-off-by: Hirokazu Honda <hiroh@chromium.org>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>

src/libcamera/meson.build

@@ -148,6 +148,7 @@ libcamera = shared_library('camera',
                            libcamera_sources,
                            install : true,
                            link_with : libcamera_link_with,
+                           cpp_args : libcamera_cpp_args,
                            include_directories : includes,
                            objects : libcamera_objects,
                            build_rpath : '/',