Add a comment about a assertion.

MyTracksTest/src/com/google/android/apps/mytracks/services/AdaptiveLocationListenerPolicyTest.java

@@ -41,7 +41,8 @@ public class AdaptiveLocationListenerPolicyTest extends TestCase {
 
   /**
    * Tests the
-   * {@link AdaptiveLocationListenerPolicy#getDesiredPollingInterval()} in four situations.
+   * {@link AdaptiveLocationListenerPolicy#getDesiredPollingInterval()} in four
+   * situations.
    * <ul>
    * <li>The newIdleTime is bigger than max interval.</li>
    * <li>The newIdleTime is between min and max interval.</li>
@@ -54,8 +55,9 @@ public class AdaptiveLocationListenerPolicyTest extends TestCase {
     assertEquals(MAX, adocationListenerPolicy.getDesiredPollingInterval());
 
     adocationListenerPolicy.updateIdleTime(NEW_IDLE_TIME_NORMAL);
-    assertEquals((NEW_IDLE_TIME_NORMAL / 2000)
-        * 1000,
+    // First get the half of NEW_IDLE_TIME_NORMAL, and then round it to the
+    // nearest second.
+    assertEquals((NEW_IDLE_TIME_NORMAL / 2 / 1000) * 1000,
         adocationListenerPolicy.getDesiredPollingInterval());
 
     adocationListenerPolicy.updateIdleTime(NEW_IDLE_TIME_SMALL);