Document that Handler.postDelayed uses uptimeMillis() based counting.
-Make it clear that delay may be longer than requested.
-Potentially help developers avoid power bugs (e.g. releasing after delay).
Bug: 12015795

Change-Id: I8034466f6307f64bfcad985948c1dc06872297d3
diff --git a/core/java/android/os/Handler.java b/core/java/android/os/Handler.java
index e6886c4..44367f3 100644
--- a/core/java/android/os/Handler.java
+++ b/core/java/android/os/Handler.java
@@ -330,6 +330,7 @@
      * Causes the Runnable r to be added to the message queue, to be run
      * at a specific time given by <var>uptimeMillis</var>.
      * <b>The time-base is {@link android.os.SystemClock#uptimeMillis}.</b>
+     * Time spent in deep sleep will add an additional delay to execution.
      * The runnable will be run on the thread to which this handler is attached.
      *
      * @param r The Runnable that will be executed.
@@ -352,6 +353,7 @@
      * Causes the Runnable r to be added to the message queue, to be run
      * at a specific time given by <var>uptimeMillis</var>.
      * <b>The time-base is {@link android.os.SystemClock#uptimeMillis}.</b>
+     * Time spent in deep sleep will add an additional delay to execution.
      * The runnable will be run on the thread to which this handler is attached.
      *
      * @param r The Runnable that will be executed.
@@ -377,6 +379,8 @@
      * after the specified amount of time elapses.
      * The runnable will be run on the thread to which this handler
      * is attached.
+     * <b>The time-base is {@link android.os.SystemClock#uptimeMillis}.</b>
+     * Time spent in deep sleep will add an additional delay to execution.
      *  
      * @param r The Runnable that will be executed.
      * @param delayMillis The delay (in milliseconds) until the Runnable
@@ -570,6 +574,7 @@
      * Enqueue a message into the message queue after all pending messages
      * before the absolute time (in milliseconds) <var>uptimeMillis</var>.
      * <b>The time-base is {@link android.os.SystemClock#uptimeMillis}.</b>
+     * Time spent in deep sleep will add an additional delay to execution.
      * You will receive it in {@link #handleMessage}, in the thread attached
      * to this handler.
      *