[Downloads] Introduce GUIDs for downloads.

components/history/core/test/history_backend_db_base_test.cc

Index: components/history/core/test/history_backend_db_base_test.cc
diff --git a/components/history/core/test/history_backend_db_base_test.cc b/components/history/core/test/history_backend_db_base_test.cc
index 7a0c1101c1fdfadc9d5d01705a03d4f08a3e8594..5d77e4f19b6195c533f38a12c1c6a4663fa211fe 100644
--- a/components/history/core/test/history_backend_db_base_test.cc
+++ b/components/history/core/test/history_backend_db_base_test.cc
@@ -117,6 +117,7 @@ void HistoryBackendDBBaseTest::DeleteBackend() {
 }
 
 bool HistoryBackendDBBaseTest::AddDownload(uint32_t id,
+                                           const std::string& guid,
                                            DownloadState state,
                                            base::Time time) {
   std::vector<GURL> url_chain;
@@ -126,6 +127,7 @@ bool HistoryBackendDBBaseTest::AddDownload(uint32_t id,
                        base::FilePath(FILE_PATH_LITERAL("target-path")),
                        url_chain,
                        GURL("http://referrer.com/"),
+                       std::string(),
                        "application/vnd.oasis.opendocument.text",
                        "application/octet-stream",
                        time,
@@ -137,7 +139,9 @@ bool HistoryBackendDBBaseTest::AddDownload(uint32_t id,
                        state,
                        DownloadDangerType::NOT_DANGEROUS,
                        kTestDownloadInterruptReasonNone,
+                       std::string(),
                        id,
+                       guid,
                        false,
                        "by_ext_id",
                        "by_ext_name");