StrictMode: link to designing for responsiveness ANR docs

Change-Id: If65849aaa8317e7e40b2837b640a5cdb95fe7b0e

core/java/android/os/StrictMode.java

@@ -38,7 +38,10 @@ import java.util.HashMap;
  * network access on the application's main thread, where UI
  * operations are received and animations take place.  Keeping disk
  * and network operations off the main thread makes for much smoother,
- * more responsive applications.
+ * more responsive applications.  By keeping your application's main thread
+ * responsive, you also prevent
+ * <a href="{@docRoot}guide/practices/design/responsiveness.html">ANR dialogs</a>
+ * from being shown to users.
  *
  * <p class="note">Note that even though an Android device's disk is
  * often on flash memory, many devices run a filesystem on top of that

docs/html/guide/practices/design/responsiveness.jd

@@ -99,6 +99,10 @@ responsive to input and thus avoid ANR dialogs caused by the 5 second input
 event timeout. These same practices should be followed for any other threads
 that display UI, as they are also subject to the same timeouts.</p>
 
+<p>You can use {@link android.os.StrictMode} to help find potentially
+long running operations such as network or database operations that
+you might accidentally be doing your main thread.</p>
+
 <p>The specific constraint on IntentReceiver execution time emphasizes what
 they were meant to do: small, discrete amounts of work in the background such
 as saving a setting or registering a Notification. So as with other methods