Add a test for nested oopif printing

When an out-of-process subframe itself also has out-of-process
subframe(s), we need to be able to embed such contents too. This
CL adds a test to make sure our code works in such cases.

BUG=853942

Change-Id: I09d1fab4f10e299d3a7fb7f164bbbcfade3eebb5
Reviewed-on: https://chromium-review.googlesource.com/1166032
Commit-Queue: Lei Zhang <thestig@chromium.org>
Reviewed-by: Lei Zhang <thestig@chromium.org>
Cr-Commit-Position: refs/heads/master@{#582027}

printing/BUILD.gn

@@ -269,6 +269,7 @@ test("printing_unittests") {
     "page_range_unittest.cc",
     "page_setup_unittest.cc",
     "pdf_metafile_cg_mac_unittest.cc",
+    "pdf_metafile_skia_unittest.cc",
     "printing_context_win_unittest.cc",
     "printing_test.h",
     "printing_utils_unittest.cc",
@@ -279,6 +280,7 @@ test("printing_unittests") {
     ":printing",
     "//base/test:run_all_unittests",
     "//base/test:test_support",
+    "//printing/common",
     "//testing/gtest",
     "//ui/base",
     "//ui/gfx",

printing/pdf_metafile_skia.cc

@@ -369,6 +369,22 @@ const ContentToProxyIdMap& PdfMetafileSkia::GetSubframeContentInfo() const {
   return data_->subframe_content_info_;
 }
 
+void PdfMetafileSkia::AppendPage(const SkSize& page_size,
+                                 sk_sp<cc::PaintRecord> record) {
+  data_->pages_.emplace_back(page_size, std::move(record));
+}
+
+void PdfMetafileSkia::AppendSubframeInfo(uint32_t content_id,
+                                         int proxy_id,
+                                         sk_sp<SkPicture> pic_holder) {
+  data_->subframe_content_info_[content_id] = proxy_id;
+  data_->subframe_pics_[content_id] = pic_holder;
+}
+
+SkStreamAsset* PdfMetafileSkia::GetPdfData() const {
+  return data_->pdf_data_.get();
+}
+
 void PdfMetafileSkia::CustomDataToSkPictureCallback(SkCanvas* canvas,
                                                     uint32_t content_id) {
   // Check whether this is the one we need to handle.

printing/pdf_metafile_skia.h

@@ -9,6 +9,7 @@
 
 #include <memory>
 
+#include "base/gtest_prod_util.h"
 #include "base/macros.h"
 #include "build/build_config.h"
 #include "cc/paint/paint_canvas.h"
@@ -96,6 +97,15 @@ class PRINTING_EXPORT PdfMetafileSkia : public Metafile {
   const ContentToProxyIdMap& GetSubframeContentInfo() const;
 
  private:
+  FRIEND_TEST_ALL_PREFIXES(PdfMetafileSkiaTest, TestFrameContent);
+
+  // The following three functions are used for tests only.
+  void AppendPage(const SkSize& page_size, sk_sp<cc::PaintRecord> record);
+  void AppendSubframeInfo(uint32_t content_id,
+                          int proxy_id,
+                          sk_sp<SkPicture> subframe_pic_holder);
+  SkStreamAsset* GetPdfData() const;
+
   // Callback function used during page content drawing to replace a custom
   // data holder with corresponding place holder SkPicture.
   void CustomDataToSkPictureCallback(SkCanvas* canvas, uint32_t content_id);

printing/pdf_metafile_skia_unittest.cc

@@ -0,0 +1,80 @@
+// Copyright 2018 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "printing/pdf_metafile_skia.h"
+
+#include "cc/paint/paint_record.h"
+#include "printing/common/pdf_metafile_utils.h"
+#include "testing/gtest/include/gtest/gtest.h"
+#include "third_party/skia/include/core/SkPictureRecorder.h"
+
+namespace printing {
+
+TEST(PdfMetafileSkiaTest, TestFrameContent) {
+  constexpr int kPictureSideLen = 100;
+  constexpr int kPageSideLen = 150;
+
+  // Create a placeholder picture.
+  sk_sp<SkPicture> pic_holder = SkPicture::MakePlaceholder(
+      SkRect::MakeXYWH(0, 0, kPictureSideLen, kPictureSideLen));
+
+  // Create the page with nested content which is the placeholder and will be
+  // replaced later.
+  sk_sp<cc::PaintRecord> record = sk_make_sp<cc::PaintRecord>();
+  cc::PaintFlags flags;
+  flags.setColor(SK_ColorWHITE);
+  const SkRect page_rect = SkRect::MakeXYWH(0, 0, kPageSideLen, kPageSideLen);
+  record->push<cc::DrawRectOp>(page_rect, flags);
+  const uint32_t content_id = pic_holder->uniqueID();
+  record->push<cc::CustomDataOp>(content_id);
+  SkSize page_size = SkSize::Make(kPageSideLen, kPageSideLen);
+
+  // Finish creating the entire metafile.
+  PdfMetafileSkia metafile(SkiaDocumentType::MSKP, 1);
+  metafile.AppendPage(page_size, std::move(record));
+  metafile.AppendSubframeInfo(content_id, 2, std::move(pic_holder));
+  metafile.FinishFrameContent();
+  SkStreamAsset* metafile_stream = metafile.GetPdfData();
+  ASSERT_TRUE(metafile_stream);
+
+  // Draw a 100 by 100 red square which will be the actual content of
+  // the placeholder.
+  SkPictureRecorder recorder;
+  SkCanvas* canvas = recorder.beginRecording(kPictureSideLen, kPictureSideLen);
+  SkPaint paint;
+  paint.setStyle(SkPaint::kStrokeAndFill_Style);
+  paint.setColor(SK_ColorRED);
+  paint.setAlpha(SK_AlphaOPAQUE);
+  canvas->drawRect(SkRect::MakeXYWH(0, 0, kPictureSideLen, kPictureSideLen),
+                   paint);
+  sk_sp<SkPicture> picture(recorder.finishRecordingAsPicture());
+  EXPECT_TRUE(picture);
+
+  // Get the complete picture by replacing the placeholder.
+  DeserializationContext subframes;
+  subframes[content_id] = picture;
+  SkDeserialProcs procs = DeserializationProcs(&subframes);
+  sk_sp<SkPicture> pic = SkPicture::MakeFromStream(metafile_stream, &procs);
+  ASSERT_TRUE(pic);
+
+  // Verify the resultant picture is as expected by comparing the sizes and
+  // detecting the color inside and outside of the square area.
+  EXPECT_TRUE(pic->cullRect() == page_rect);
+  SkBitmap bitmap;
+  bitmap.allocN32Pixels(kPageSideLen, kPageSideLen);
+  SkCanvas bitmap_canvas(bitmap);
+  pic->playback(&bitmap_canvas);
+  // Check top left pixel color of the red square.
+  EXPECT_EQ(bitmap.getColor(0, 0), SK_ColorRED);
+  // Check bottom right pixel of the red square.
+  EXPECT_EQ(bitmap.getColor(kPictureSideLen - 1, kPictureSideLen - 1),
+            SK_ColorRED);
+  // Check inside of the red square.
+  EXPECT_EQ(bitmap.getColor(kPictureSideLen / 2, kPictureSideLen / 2),
+            SK_ColorRED);
+  // Check outside of the red square.
+  EXPECT_EQ(bitmap.getColor(kPictureSideLen, kPictureSideLen), SK_ColorWHITE);
+}
+
+}  // namespace printing