Merge sub-device annotations in SkPDFDevice::drawDevice()

gm/annotated_text.cpp

 /*
  * Copyright 2015 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #include "SkAnnotation.h"
 #include "SkData.h"
 #include "gm.h"
@@ skipping 16 matching lines @@
 DEF_SIMPLE_GM(annotated_text, canvas, 512, 512) {
     SkAutoCanvasRestore autoCanvasRestore(canvas, true);
     canvas->clear(SK_ColorWHITE);
     canvas->clipRect(SkRect::MakeXYWH(64, 64, 256, 256));
     canvas->clear(0xFFEEEEEE);
     SkPaint p;
     p.setTextSize(40);
     const char text[] = "Click this link!";
     const char url[] = "https://www.google.com/";
     draw_url_annotated_text_with_box(canvas, text, 200.0f, 80.0f, p, url);
-    SkAutoCanvasRestore autoCanvasRestore2(canvas, true);
+    canvas->saveLayer(nullptr, nullptr);
     canvas->rotate(90);
     draw_url_annotated_text_with_box(canvas, text, 150.0f, -55.0f, p, url);
+    canvas->restore();
 }