Allow single press of physical button to go home without sleeping.

Bug: 18921423
Change-Id: Ic7ee7daeaf1b4e08a7c53451615736ee7a08fb61

core/java/android/view/WindowManagerPolicy.java

@@ -17,6 +17,7 @@
 package android.view;
 
 import android.annotation.IntDef;
+import android.annotation.SystemApi;
 import android.content.Context;
 import android.content.pm.ActivityInfo;
 import android.content.res.CompatibilityInfo;
@@ -104,6 +105,13 @@ public interface WindowManagerPolicy {
      */
     public final static String EXTRA_HDMI_PLUGGED_STATE = "state";
 
+    /**
+     * Set to {@code true} when intent was invoked from pressing the home key.
+     * @hide
+     */
+    @SystemApi
+    public static final String EXTRA_FROM_HOME_KEY = "android.intent.extra.FROM_HOME_KEY";
+
     /**
      * Pass this event to the user / app.  To be returned from
      * {@link #interceptKeyBeforeQueueing}.