Clarify Beacon transmission limit checking.

third_party/WebKit/Source/core/loader/PingLoader.cpp

 /*
  * Copyright (C) 2010 Google Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are
  * met:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
  *     * Redistributions in binary form must reproduce the above
@@ skipping 402 matching lines @@
 
   // The loader keeps itself alive until it receives a response and disposes
   // itself.
   PingLoaderImpl* loader =
       new PingLoaderImpl(frame, request, initiator, credentialsAllowed, true);
   DCHECK(loader);
 
   return true;
 }
 
+// Decide if a beacon with the given size is allowed to go ahead
+// given some overall allowance limit.
+bool allowBeaconWithSize(int allowance, unsigned long long size) {
+  // If a negative allowance is supplied, no size constraint is imposed.
+  if (allowance < 0)
+    return true;
+
+  if (static_cast<unsigned long long>(allowance) < size)
+    return false;
+
+  return true;
+}
+
 bool sendBeaconCommon(LocalFrame* frame,
                       int allowance,
                       const KURL& url,
                       const Beacon& beacon,
-                      int& payloadLength) {
+                      size_t& beaconSize) {
   if (!frame->document())
     return false;
 
   // TODO(mkwst): CSP is not enforced on redirects, crbug.com/372197
   if (!ContentSecurityPolicy::shouldBypassMainWorld(frame->document()) &&
       !frame->document()->contentSecurityPolicy()->allowConnectToSource(url)) {
     // We're simulating a network failure here, so we return 'true'.
     return true;
   }
 
-  unsigned long long entitySize = beacon.size();
-  if (allowance < 0 || static_cast<unsigned long long>(allowance) < entitySize)
+  unsigned long long size = beacon.size();
+  if (!allowBeaconWithSize(allowance, size))
     return false;
 
-  payloadLength = entitySize;
+  beaconSize = size;
 
   ResourceRequest request(url);
   request.setHTTPMethod(HTTPNames::POST);
   request.setHTTPHeaderField(HTTPNames::Cache_Control, "max-age=0");
   finishPingRequestInitialization(request, frame,
                                   WebURLRequest::RequestContextBeacon);
 
   beacon.serialize(request);
 
   return sendPingCommon(frame, request, FetchInitiatorTypeNames::beacon,
@@ skipping 81 matching lines @@
           ? AllowStoredCredentials
           : DoNotAllowStoredCredentials;
   sendPingCommon(frame, request, FetchInitiatorTypeNames::violationreport,
                  credentialsAllowed, false);
 }
 
 bool PingLoader::sendBeacon(LocalFrame* frame,
                             int allowance,
                             const KURL& beaconURL,
                             const String& data,
-                            int& payloadLength) {
+                            size_t& beaconSize) {
   BeaconString beacon(data);
-  return sendBeaconCommon(frame, allowance, beaconURL, beacon, payloadLength);
+  return sendBeaconCommon(frame, allowance, beaconURL, beacon, beaconSize);
 }
 
 bool PingLoader::sendBeacon(LocalFrame* frame,
                             int allowance,
                             const KURL& beaconURL,
                             DOMArrayBufferView* data,
-                            int& payloadLength) {
+                            size_t& beaconSize) {
   BeaconDOMArrayBufferView beacon(data);
-  return sendBeaconCommon(frame, allowance, beaconURL, beacon, payloadLength);
+  return sendBeaconCommon(frame, allowance, beaconURL, beacon, beaconSize);
 }
 
 bool PingLoader::sendBeacon(LocalFrame* frame,
                             int allowance,
                             const KURL& beaconURL,
                             FormData* data,
-                            int& payloadLength) {
+                            size_t& beaconSize) {
   BeaconFormData beacon(data);
-  return sendBeaconCommon(frame, allowance, beaconURL, beacon, payloadLength);
+  return sendBeaconCommon(frame, allowance, beaconURL, beacon, beaconSize);
 }
 
 bool PingLoader::sendBeacon(LocalFrame* frame,
                             int allowance,
                             const KURL& beaconURL,
                             Blob* data,
-                            int& payloadLength) {
+                            size_t& beaconSize) {
   BeaconBlob beacon(data);
-  return sendBeaconCommon(frame, allowance, beaconURL, beacon, payloadLength);
+  return sendBeaconCommon(frame, allowance, beaconURL, beacon, beaconSize);
 }
 
 }  // namespace blink