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

google_apis/drive/drive_api_url_generator.cc

Index: google_apis/drive/drive_api_url_generator.cc
diff --git a/google_apis/drive/drive_api_url_generator.cc b/google_apis/drive/drive_api_url_generator.cc
index e79bf0decca7285d8673d9767bc6f870ba3c6c7d..c257e3c5de8c20104f91344cfc4605fc161cea94 100644
--- a/google_apis/drive/drive_api_url_generator.cc
+++ b/google_apis/drive/drive_api_url_generator.cc
@@ -23,6 +23,8 @@ namespace {
 const char kDriveV2AboutUrl[] = "drive/v2/about";
 const char kDriveV2AppsUrl[] = "drive/v2/apps";
 const char kDriveV2ChangelistUrl[] = "drive/v2/changes";
+const char kDriveV2ChangesGetStartPageTokenUrl[] =
+    "drive/v2/changes/startPageToken";
 const char kDriveV2FilesUrl[] = "drive/v2/files";
 const char kDriveV2FileUrlPrefix[] = "drive/v2/files/";
 const char kDriveV2ChildrenUrlFormat[] = "drive/v2/files/%s/children";
@@ -223,6 +225,19 @@ GURL DriveApiUrlGenerator::GetFilesTrashUrl(const std::string& file_id) const {
   return url;
 }
 
+GURL DriveApiUrlGenerator::GetChangesGetStartPageTokenUrl(
+    const std::string& team_drive_id) const {
+  GURL url = base_url_.Resolve(kDriveV2ChangesGetStartPageTokenUrl);
+  if (enable_team_drives_) {
+    url = net::AppendOrReplaceQueryParameter(url, kSupportsTeamDrives, "true");
+    if (!team_drive_id.empty()) {
+      url =
+          net::AppendOrReplaceQueryParameter(url, "teamDriveId", team_drive_id);
+    }
+  }
+  return url;
+}
+
 GURL DriveApiUrlGenerator::GetChangesListUrl(
     bool include_deleted,
     int max_results,