Add UMA metric to track parallel download requests stats.

content/browser/download/parallel_download_job_unittest.cc

Index: content/browser/download/parallel_download_job_unittest.cc
diff --git a/content/browser/download/parallel_download_job_unittest.cc b/content/browser/download/parallel_download_job_unittest.cc
index e31fb45a2a36d3844dc943fe103fcadb8fe3ecc4..de6da07deda379c106927e458ac183375c69ee02 100644
--- a/content/browser/download/parallel_download_job_unittest.cc
+++ b/content/browser/download/parallel_download_job_unittest.cc
@@ -77,7 +77,6 @@ class ParallelDownloadJobForTest : public ParallelDownloadJob {
 class ParallelDownloadJobTest : public testing::Test {
  public:
   void CreateParallelJob(int64_t initial_request_offset,
-                         int64_t initial_request_length,
                          int64_t content_length,
                          const DownloadItem::ReceivedSlices& slices,
                          int request_count,
@@ -87,7 +86,6 @@ class ParallelDownloadJobTest : public testing::Test {
         item_delegate_.get(), slices);
     DownloadCreateInfo info;
     info.offset = initial_request_offset;
-    info.length = initial_request_length;
     info.total_bytes = content_length;
     std::unique_ptr<MockDownloadRequestHandle> request_handle =
         base::MakeUnique<MockDownloadRequestHandle>();
@@ -141,7 +139,7 @@ TEST_F(ParallelDownloadJobTest, CreateNewDownloadRequestsWithoutSlices) {
   // Totally 2 requests for 100 bytes.
   // Original request:  Range:0-49, for 50 bytes.
   // Task 1:  Range:50-, for 50 bytes.
-  CreateParallelJob(0, 0, 100, DownloadItem::ReceivedSlices(), 2, 1);
+  CreateParallelJob(0, 100, DownloadItem::ReceivedSlices(), 2, 1);
   BuildParallelRequests();
   EXPECT_EQ(1, static_cast<int>(job_->workers().size()));
   VerifyWorker(50, 0);
@@ -151,7 +149,7 @@ TEST_F(ParallelDownloadJobTest, CreateNewDownloadRequestsWithoutSlices) {
   // Original request:  Range:0-32, for 33 bytes.
   // Task 1:  Range:33-65, for 33 bytes.
   // Task 2:  Range:66-, for 34 bytes.
-  CreateParallelJob(0, 0, 100, DownloadItem::ReceivedSlices(), 3, 1);
+  CreateParallelJob(0, 100, DownloadItem::ReceivedSlices(), 3, 1);
   BuildParallelRequests();
   EXPECT_EQ(2, static_cast<int>(job_->workers().size()));
   VerifyWorker(33, 33);
@@ -159,18 +157,18 @@ TEST_F(ParallelDownloadJobTest, CreateNewDownloadRequestsWithoutSlices) {
   DestroyParallelJob();
 
   // Less than 2 requests, do nothing.
-  CreateParallelJob(0, 0, 100, DownloadItem::ReceivedSlices(), 1, 1);
+  CreateParallelJob(0, 100, DownloadItem::ReceivedSlices(), 1, 1);
   BuildParallelRequests();
   EXPECT_TRUE(job_->workers().empty());
   DestroyParallelJob();
 
-  CreateParallelJob(0, 0, 100, DownloadItem::ReceivedSlices(), 0, 1);
+  CreateParallelJob(0, 100, DownloadItem::ReceivedSlices(), 0, 1);
   BuildParallelRequests();
   EXPECT_TRUE(job_->workers().empty());
   DestroyParallelJob();
 
   // Content-length is 0, do nothing.
-  CreateParallelJob(0, 0, 0, DownloadItem::ReceivedSlices(), 3, 1);
+  CreateParallelJob(0, 0, DownloadItem::ReceivedSlices(), 3, 1);
   BuildParallelRequests();
   EXPECT_TRUE(job_->workers().empty());
   DestroyParallelJob();
@@ -185,7 +183,7 @@ TEST_F(ParallelDownloadJobTest, CreateNewDownloadRequestsWithSlices) {
   // Task 1:  Range:44-70, for 27 bytes.
   // Task 2:  Range:71-, for 29 bytes.
   DownloadItem::ReceivedSlices slices = {DownloadItem::ReceivedSlice(0, 17)};
-  CreateParallelJob(12, 0, 88, slices, 3, 1);
+  CreateParallelJob(12, 88, slices, 3, 1);
   BuildParallelRequests();
   EXPECT_EQ(2, static_cast<int>(job_->workers().size()));
   VerifyWorker(44, 27);
@@ -199,7 +197,7 @@ TEST_F(ParallelDownloadJobTest, CreateNewDownloadRequestsWithSlices) {
   // Original request: Range:98-99, for 1 bytes.
   // Task 1:  Range:99-, for 1 bytes.
   slices = {DownloadItem::ReceivedSlice(0, 98)};
-  CreateParallelJob(98, 0, 2, slices, 4, 1);
+  CreateParallelJob(98, 2, slices, 4, 1);
   BuildParallelRequests();
   EXPECT_EQ(1, static_cast<int>(job_->workers().size()));
   VerifyWorker(99, 0);
@@ -207,7 +205,7 @@ TEST_F(ParallelDownloadJobTest, CreateNewDownloadRequestsWithSlices) {
 
   // Content-Length is 0, no additional requests.
   slices = {DownloadItem::ReceivedSlice(0, 100)};
-  CreateParallelJob(100, 0, 0, slices, 3, 1);
+  CreateParallelJob(100, 0, slices, 3, 1);
   BuildParallelRequests();
   EXPECT_TRUE(job_->workers().empty());
   DestroyParallelJob();
@@ -220,7 +218,7 @@ TEST_F(ParallelDownloadJobTest, CreateNewDownloadRequestsWithSlices) {
   slices = {
       DownloadItem::ReceivedSlice(10, 10), DownloadItem::ReceivedSlice(20, 10),
       DownloadItem::ReceivedSlice(40, 10), DownloadItem::ReceivedSlice(90, 10)};
-  CreateParallelJob(0, 0, 12, slices, 2, 1);
+  CreateParallelJob(0, 12, slices, 2, 1);
   BuildParallelRequests();
   EXPECT_EQ(3, static_cast<int>(job_->workers().size()));
   VerifyWorker(30, 10);
@@ -229,31 +227,6 @@ TEST_F(ParallelDownloadJobTest, CreateNewDownloadRequestsWithSlices) {
   DestroyParallelJob();
 }
 
-// Ensure the holes before the initial request offset is patched up with
-// parallel requests.
-// This may happen when the previous session is non-parallel but the new
-// session is parallel, and etag doesn't change.
-TEST_F(ParallelDownloadJobTest, CreateNewRequestsIncorrectInitOffset) {
-  // Although we can parallel 4 requests, but we find 2 holes, so just patch
-  // them up with 2 requests.
-  // The offset of 2 slices to download are before the initial request offset.
-  DownloadItem::ReceivedSlices slices = {DownloadItem::ReceivedSlice(40, 5)};
-  CreateParallelJob(50, 0, 50, slices, 4, 1);
-  BuildParallelRequests();
-  EXPECT_EQ(2, static_cast<int>(job_->workers().size()));
-  VerifyWorker(0, 40);
-  VerifyWorker(45, 0);
-  DestroyParallelJob();
-
-  // There is one slice to download before initial request offset, so we just
-  // build one request.
-  CreateParallelJob(50, 0, 50, DownloadItem::ReceivedSlices(), 4, 1);
-  BuildParallelRequests();
-  EXPECT_EQ(1, static_cast<int>(job_->workers().size()));
-  VerifyWorker(0, 0);
-  DestroyParallelJob();
-}
-
 // Pause, cancel, resume can be called before or after the worker establish
 // the byte stream.
 // These tests ensure the states consistency between the job and workers.
@@ -261,7 +234,7 @@ TEST_F(ParallelDownloadJobTest, CreateNewRequestsIncorrectInitOffset) {
 // Ensure cancel before building the requests will result in no requests are
 // built.
 TEST_F(ParallelDownloadJobTest, EarlyCancelBeforeBuildRequests) {
-  CreateParallelJob(0, 0, 100, DownloadItem::ReceivedSlices(), 2, 1);
+  CreateParallelJob(0, 100, DownloadItem::ReceivedSlices(), 2, 1);
   EXPECT_CALL(*mock_request_handle_, CancelRequest());
 
   // Job is canceled before building parallel requests.
@@ -277,7 +250,7 @@ TEST_F(ParallelDownloadJobTest, EarlyCancelBeforeBuildRequests) {
 // Ensure cancel before adding the byte stream will result in workers being
 // canceled.
 TEST_F(ParallelDownloadJobTest, EarlyCancelBeforeByteStreamReady) {
-  CreateParallelJob(0, 0, 100, DownloadItem::ReceivedSlices(), 2, 1);
+  CreateParallelJob(0, 100, DownloadItem::ReceivedSlices(), 2, 1);
   EXPECT_CALL(*mock_request_handle_, CancelRequest());
 
   BuildParallelRequests();
@@ -301,7 +274,7 @@ TEST_F(ParallelDownloadJobTest, EarlyCancelBeforeByteStreamReady) {
 // Ensure pause before adding the byte stream will result in workers being
 // paused.
 TEST_F(ParallelDownloadJobTest, EarlyPauseBeforeByteStreamReady) {
-  CreateParallelJob(0, 0, 100, DownloadItem::ReceivedSlices(), 2, 1);
+  CreateParallelJob(0, 100, DownloadItem::ReceivedSlices(), 2, 1);
   EXPECT_CALL(*mock_request_handle_, PauseRequest());
 
   BuildParallelRequests();