Add an abstraction for a job in the AppCacheRequestHandler class.

content/browser/BUILD.gn

Index: content/browser/BUILD.gn
diff --git a/content/browser/BUILD.gn b/content/browser/BUILD.gn
index cfebe3dff403e6f47ad6ffd62a8a496e74f2b796..c57e9129d5e94918fda08ca5f8ae6bdd838a1db3 100644
--- a/content/browser/BUILD.gn
+++ b/content/browser/BUILD.gn
@@ -308,6 +308,8 @@ source_set("browser") {
     "appcache/appcache_interceptor.h",
     "appcache/appcache_internals_ui.cc",
     "appcache/appcache_internals_ui.h",
+    "appcache/appcache_job.cc",
+    "appcache/appcache_job.h",
     "appcache/appcache_manifest_parser.cc",
     "appcache/appcache_manifest_parser.h",
     "appcache/appcache_navigation_handle.cc",
@@ -331,6 +333,8 @@ source_set("browser") {
     "appcache/appcache_storage_impl.h",
     "appcache/appcache_update_job.cc",
     "appcache/appcache_update_job.h",
+    "appcache/appcache_url_loader_job.cc",
+    "appcache/appcache_url_loader_job.h",
     "appcache/appcache_url_loader_request.cc",
     "appcache/appcache_url_loader_request.h",
     "appcache/appcache_url_request.cc",