Add back and deprecate old methods.

src/libstd/time/duration.rs

@@ -96,13 +96,30 @@ impl Duration {
     #[stable(feature = "duration", since = "1.3.0")]
     pub fn as_secs(&self) -> u64 { self.secs }
 
+    #[deprecated(reason = "renamed to `as_secs`", since = "1.3.0")]
+    #[unstable(feature = "duration_deprecated")]
+    /// Returns the number of whole seconds represented by this duration.
+    ///
+    /// The extra precision represented by this duration is ignored (e.g. extra
+    /// nanoseconds are not represented in the returned value).
+    pub fn secs(&self) -> u64 { self.as_secs() }
+
     /// Returns the nanosecond precision represented by this duration.
     ///
     /// This method does **not** return the length of the duration when
     /// represented by nanoseconds. The returned number always represents a
     /// fractional portion of a second (e.g. it is less than one billion).
     #[stable(feature = "duration", since = "1.3.0")]
     pub fn subsec_nanos(&self) -> u32 { self.nanos }
+
+    #[deprecated(reason = "renamed to `subsec_nanos`", since = "1.3.0")]
+    #[unstable(feature = "duration_deprecated")]
+    /// Returns the nanosecond precision represented by this duration.
+    ///
+    /// This method does **not** return the length of the duration when
+    /// represented by nanoseconds. The returned number always represents a
+    /// fractional portion of a second (e.g. it is less than one billion).
+    pub fn extra_nanos(&self) -> u32 { self.subsec_nanos() }
 }
 
 impl Add for Duration {