Remove duplication

Author: pitdicker

src/rngs/os.rs

@@ -535,32 +535,9 @@ mod imp {
 }
 
 
-#[cfg(any(target_os = "dragonfly", target_os = "haiku"))]
-mod imp {
-    use Error;
-    use super::random_device;
-    use super::OsRngImpl;
-    use std::fs::File;
-
-    #[derive(Clone, Debug)]
-    pub struct OsRng();
-
-    impl OsRngImpl for OsRng {
-        fn new() -> Result<OsRng, Error> {
-            random_device::open("/dev/random", &|p| File::open(p))?;
-            Ok(OsRng())
-        }
-
-        fn fill_chunk(&mut self, dest: &mut [u8]) -> Result<(), Error> {
-            random_device::read(dest)
-        }
-
-        fn method_str(&self) -> &'static str { "/dev/random" }
-    }
-}
-
-
-#[cfg(target_os = "emscripten")]
+#[cfg(any(target_os = "dragonfly",
+          target_os = "haiku",
+          target_os = "emscripten"))]
 mod imp {
     use Error;
     use super::random_device;
@@ -580,6 +557,7 @@ mod imp {
             random_device::read(dest)
         }
 
+        #[cfg(target_os = "emscripten")]
         fn max_chunk_size(&self) -> usize {
             // `Crypto.getRandomValues` documents `dest` should be at most 65536
             // bytes. `crypto.randomBytes` documents: "To minimize threadpool