Update the received slices vector when stream is written to disk

content/browser/download/parallel_download_utils_unittest.cc

 // Copyright 2017 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 "content/browser/download/parallel_download_utils.h"
 
 #include "content/public/browser/download_save_info.h"
 #include "testing/gtest/include/gtest/gtest.h"
 
 namespace content {
@@ skipping 37 matching lines @@
   downloaded_slices.erase(downloaded_slices.begin());
   slices_to_download = FindSlicesToDownload(downloaded_slices);
   EXPECT_EQ(2u, slices_to_download.size());
   EXPECT_EQ(0, slices_to_download[0].offset);
   EXPECT_EQ(500, slices_to_download[0].received_bytes);
   EXPECT_EQ(1500, slices_to_download[1].offset);
   EXPECT_EQ(DownloadSaveInfo::kLengthFullContent,
             slices_to_download[1].received_bytes);
 }
 
+TEST(ParallelDownloadUtilsTest, AddOrMergeReceivedSliceIntoSortedArray) {
+  std::vector<DownloadItem::ReceivedSlice> slices;
+  DownloadItem::ReceivedSlice slice1(500, 500);
+  EXPECT_EQ(0u, AddOrMergeReceivedSliceIntoSortedArray(slice1, slices));
+  EXPECT_EQ(1u, slices.size());
+  EXPECT_EQ(slice1, slices[0]);
+
+  // Adding a slice that can be merged with existing slice.
+  DownloadItem::ReceivedSlice slice2(1000, 400);
+  EXPECT_EQ(0u, AddOrMergeReceivedSliceIntoSortedArray(slice2, slices));
+  EXPECT_EQ(1u, slices.size());
+  EXPECT_EQ(500, slices[0].offset);
+  EXPECT_EQ(900, slices[0].received_bytes);
+
+  DownloadItem::ReceivedSlice slice3(0, 50);
+  EXPECT_EQ(0u, AddOrMergeReceivedSliceIntoSortedArray(slice3, slices));
+  EXPECT_EQ(2u, slices.size());
+  EXPECT_EQ(slice3, slices[0]);
+
+  DownloadItem::ReceivedSlice slice4(100, 50);
+  EXPECT_EQ(1u, AddOrMergeReceivedSliceIntoSortedArray(slice4, slices));
+  EXPECT_EQ(3u, slices.size());
+  EXPECT_EQ(slice3, slices[0]);
+  EXPECT_EQ(slice4, slices[1]);
+
+  // A new slice can only merge with a slice in front of it, not behind it.
+  DownloadItem::ReceivedSlice slice5(50, 50);
+  EXPECT_EQ(0u, AddOrMergeReceivedSliceIntoSortedArray(slice5, slices));
+  EXPECT_EQ(3u, slices.size());
+  EXPECT_EQ(0, slices[0].offset);
+  EXPECT_EQ(100, slices[0].received_bytes);
+  EXPECT_EQ(slice4, slices[1]);
+
+}
+
 }  // namespace content