SampleApp fixes.

On Android, delete gWindow before calling application_term, avoiding a crash
each time the app closes.  Also make sure the screen is redrawn when resuming.

On Linux, delete gWindow to avoid memory leak.

In general, allow moving from sample 0 to the last sample.

Reviewed at http://codereview.appspot.com/4639060


git-svn-id: http://skia.googlecode.com/svn/trunk@1661 2bbb7eff-a529-9590-31e7-b0007b416f81
diff --git a/unix_test_app/main.cpp b/unix_test_app/main.cpp
index 5be93bc..9dafb3c 100644
--- a/unix_test_app/main.cpp
+++ b/unix_test_app/main.cpp
@@ -25,6 +25,7 @@
 
     gWindow->loop();
 
+    delete gWindow;
     application_term();
     return 0;
 }