Add a way to save to PDF in SampleApp on Android and elsewhere.

In Android, add the PDF file to downloads, so it can be opened.

Reviewed at http://codereview.appspot.com/4638052/


git-svn-id: http://skia.googlecode.com/svn/trunk@1659 2bbb7eff-a529-9590-31e7-b0007b416f81
diff --git a/include/views/SkOSWindow_Android.h b/include/views/SkOSWindow_Android.h
index e547609..c84ff2e 100644
--- a/include/views/SkOSWindow_Android.h
+++ b/include/views/SkOSWindow_Android.h
@@ -29,6 +29,9 @@
     void detachGL() {}
     void presentGL() {}
 
+    virtual void onPDFSaved(const char title[], const char desc[],
+        const char path[]);
+
 protected:
     // overrides from SkWindow
     virtual void onHandleInval(const SkIRect&);