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

content/public/browser/service_worker_usage_info.cc

Index: content/public/browser/service_worker_usage_info.cc
diff --git a/content/public/browser/service_worker_usage_info.cc b/content/public/browser/service_worker_usage_info.cc
index c35d54546d47b1a780a9cbf65058d17074ea2d2d..7ed49860d1e14a72a993afba8babbf2410198d70 100644
--- a/content/public/browser/service_worker_usage_info.cc
+++ b/content/public/browser/service_worker_usage_info.cc
@@ -8,14 +8,14 @@ namespace content {
 
 ServiceWorkerUsageInfo::ServiceWorkerUsageInfo(const GURL& origin,
                                                const std::vector<GURL>& scopes)
-    : origin(origin), scopes(scopes) {
+    : origin(origin), scopes(scopes), total_size_bytes(0) {
 }
 
 ServiceWorkerUsageInfo::ServiceWorkerUsageInfo(const GURL& origin)
-    : origin(origin) {
+    : origin(origin), total_size_bytes(0) {
 }
 
-ServiceWorkerUsageInfo::ServiceWorkerUsageInfo() {
+ServiceWorkerUsageInfo::ServiceWorkerUsageInfo() : total_size_bytes(0) {
 }
 
 ServiceWorkerUsageInfo::~ServiceWorkerUsageInfo() {