Initial implementation of ServiceWorkerCache.

content/browser/service_worker/service_worker_cache.proto

Index: content/browser/service_worker/service_worker_cache.proto
diff --git a/content/browser/service_worker/service_worker_cache.proto b/content/browser/service_worker/service_worker_cache.proto
index b271df63b0ca1b1b4a7e52d413fea01b0bc1e4b9..cb4da0918cfd7fa630df4fd6ad5c33c96053f1d7 100644
--- a/content/browser/service_worker/service_worker_cache.proto
+++ b/content/browser/service_worker/service_worker_cache.proto
@@ -15,3 +15,15 @@ message ServiceWorkerCacheStorageIndex {
   }
   repeated Cache cache = 1;
 }
+
+message ServiceWorkerRequestResponseHeaders {
+  message HeaderMap {
+    required string name = 1;
+    required string value = 2;
+  }
+  required string method = 1;
+  required int32 status_code = 2;
+  required string status_text = 3;
+  repeated HeaderMap request_headers = 4;
+  repeated HeaderMap response_headers = 5;
+}