9 (docs-only) RFR: 8180428: Clarify implementation note in Clock.java to match implementation changes made by JDK-8068730

[Daniel Fuchs]

Hi,

Please find below a clarification of the implementation note
in Clock.java:

8180428: Clarify implementation note in Clock.java to match 
implementation changes made by JDK-8068730
https://bugs.openjdk.java.net/browse/JDK-8180428

The change below was already discussed here:
http://mail.openjdk.java.net/pipermail/core-libs-dev/2017-May/047671.html

-- daniel

Here is the proposed diff:

diff --git a/src/java.base/share/classes/java/time/Clock.java 
b/src/java.base/share/classes/java/time/Clock.java
--- a/src/java.base/share/classes/java/time/Clock.java
+++ b/src/java.base/share/classes/java/time/Clock.java
@@ -127,10 +127,13 @@
   * document whether or not they do support serialization.
   *
   * @implNote
- * The clock implementation provided here is based on {@link 
System#currentTimeMillis()}.
- * That method provides little to no guarantee about the accuracy of 
the clock.
- * Applications requiring a more accurate clock must implement this 
abstract class
- * themselves using a different external clock, such as an NTP server.
+ * The clock implementation provided here is based on the same 
underlying clock
+ * as {@link System#currentTimeMillis()}, but may have a precision 
finer than
+ * milliseconds if available.
+ * However, little to no guarantee is provided about the accuracy of the
+ * underlying clock. Applications requiring a more accurate clock must 
implement
+ * this abstract class themselves using a different external clock, 
such as an
+ * NTP server.
   *
   * @since 1.8
   */