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/samplecode/SampleApp.h b/samplecode/SampleApp.h
index a58c688..4d16121 100644
--- a/samplecode/SampleApp.h
+++ b/samplecode/SampleApp.h
@@ -61,6 +61,7 @@
     bool handleTouch(int ownerId, float x, float y,
             SkView::Click::State state);
     void saveToPdf();
+    void postInvalDelay();
 
 protected:
     virtual void onDraw(SkCanvas* canvas);