Add new UMA stats for parallelizable download

content/public/test/test_file_error_injector.cc

Index: content/public/test/test_file_error_injector.cc
diff --git a/content/public/test/test_file_error_injector.cc b/content/public/test/test_file_error_injector.cc
index 867d1a00d3cff345101ed4bc288c190c9f9a4eb6..b663fe23ee6b8ff239457d4130dc527498965eb5 100644
--- a/content/public/test/test_file_error_injector.cc
+++ b/content/public/test/test_file_error_injector.cc
@@ -43,7 +43,8 @@ class DownloadFileWithError: public DownloadFileImpl {
   ~DownloadFileWithError() override;
 
   void Initialize(const InitializeCallback& callback,
-                  const DownloadItem::ReceivedSlices& received_slices) override;
+                  const DownloadItem::ReceivedSlices& received_slices,
+                  bool is_parallelizable) override;
 
   // DownloadFile interface.
   DownloadInterruptReason WriteDataToFile(int64_t offset,
@@ -134,7 +135,8 @@ DownloadFileWithError::~DownloadFileWithError() {
 
 void DownloadFileWithError::Initialize(
     const InitializeCallback& callback,
-    const DownloadItem::ReceivedSlices& received_slices) {
+    const DownloadItem::ReceivedSlices& received_slices,
+    bool is_parallelizable) {
   DownloadInterruptReason error_to_return = DOWNLOAD_INTERRUPT_REASON_NONE;
   InitializeCallback callback_to_use = callback;
 
@@ -156,7 +158,8 @@ void DownloadFileWithError::Initialize(
                                  error_to_return);
   }
 
-  DownloadFileImpl::Initialize(callback_to_use, received_slices);
+  DownloadFileImpl::Initialize(callback_to_use, received_slices,
+                               is_parallelizable);
 }
 
 DownloadInterruptReason DownloadFileWithError::WriteDataToFile(