[ServiceWorker] Added size deltas and total size computation for QuotaM.

content/browser/service_worker/service_worker_quota_client.cc

Index: content/browser/service_worker/service_worker_quota_client.cc
diff --git a/content/browser/service_worker/service_worker_quota_client.cc b/content/browser/service_worker/service_worker_quota_client.cc
index e2697e2303a62054a46c8736bac95798123ba30d..8cb7e3bf64d6385aa55859a43d9a23d7f87d58cc 100644
--- a/content/browser/service_worker/service_worker_quota_client.cc
+++ b/content/browser/service_worker/service_worker_quota_client.cc
@@ -30,6 +30,18 @@ void ReportToQuotaStatus(const QuotaClient::DeletionCallback& callback,
   callback.Run(status ? storage::QuotaStatusCode::kQuotaStatusOk
                       : storage::QuotaStatusCode::kQuotaStatusUnknown);
 }
+
+void AccumulateUsage(const QuotaClient::GetUsageCallback& callback,
+                     const GURL& origin,
+                     const std::vector<ServiceWorkerUsageInfo>& usage_info) {
+  int64 usage_total = 0;
+  for (const auto& info : usage_info) {
+    if (info.origin == origin) {
+      usage_total += info.total_size_bytes;
+    }
+  }
+  callback.Run(usage_total);
+}
 }  // namespace
 
 ServiceWorkerQuotaClient::ServiceWorkerQuotaClient(
@@ -52,8 +64,11 @@ void ServiceWorkerQuotaClient::GetOriginUsage(
     const GURL& origin,
     storage::StorageType type,
     const GetUsageCallback& callback) {
-  // TODO(dmurph): Add usage fetching when information is available.
-  callback.Run(0);
+  if (type != storage::StorageType::kStorageTypeTemporary) {
+    callback.Run(0);
+    return;
+  }
+  context_->GetAllOriginsInfo(base::Bind(&AccumulateUsage, callback, origin));
 }
 
 void ServiceWorkerQuotaClient::GetOriginsForType(