Add URL generator / json parser for getting start_page_token of changes.

google_apis/drive/drive_api_url_generator_unittest.cc

Index: google_apis/drive/drive_api_url_generator_unittest.cc
diff --git a/google_apis/drive/drive_api_url_generator_unittest.cc b/google_apis/drive/drive_api_url_generator_unittest.cc
index 43bc4524b7d1d840cb30127e1c8afae6af33d30f..86d2c9052c9de5d2313f1554324cc42e531f1a31 100644
--- a/google_apis/drive/drive_api_url_generator_unittest.cc
+++ b/google_apis/drive/drive_api_url_generator_unittest.cc
@@ -254,6 +254,21 @@ TEST_F(DriveApiUrlGeneratorTest, GetFilesTrashUrl) {
       team_drives_url_generator_.GetFilesTrashUrl("0ADK06pfg").spec());
 }
 
+TEST_F(DriveApiUrlGeneratorTest, GetChangesGetStartPageTokenUrl) {
+  EXPECT_EQ(
+      "https://www.example.com/drive/v2/changes/startPageToken?"
+      "supportsTeamDrives=true",
+      team_drives_url_generator_
+          .GetChangesGetStartPageTokenUrl("" /* team_drive_id */)
+          .spec());
+  EXPECT_EQ(
+      "https://www.example.com/drive/v2/changes/startPageToken?"
+      "supportsTeamDrives=true&teamDriveId=TheTeamDriveId",
+      team_drives_url_generator_
+          .GetChangesGetStartPageTokenUrl("TheTeamDriveId")
+          .spec());
+}
+
 TEST_F(DriveApiUrlGeneratorTest, GetChangesListUrl) {
   struct TestPattern {
     bool include_deleted;