Fetch API: Stop lowercasing header names.

third_party/WebKit/Source/modules/fetch/FetchManager.cpp

Index: third_party/WebKit/Source/modules/fetch/FetchManager.cpp
diff --git a/third_party/WebKit/Source/modules/fetch/FetchManager.cpp b/third_party/WebKit/Source/modules/fetch/FetchManager.cpp
index f91e11fdfced67796fcb74a4d96b064b3b371cad..f0c2fdc5eeba40783928ee135d868b5152d39d8c 100644
--- a/third_party/WebKit/Source/modules/fetch/FetchManager.cpp
+++ b/third_party/WebKit/Source/modules/fetch/FetchManager.cpp
@@ -716,11 +716,9 @@ void FetchManager::Loader::PerformHTTPFetch(bool cors_flag,
   request.SetHTTPMethod(request_->Method());
   request.SetFetchRequestMode(request_->Mode());
   request.SetFetchCredentialsMode(request_->Credentials());
-  const Vector<std::unique_ptr<FetchHeaderList::Header>>& list =
-      request_->HeaderList()->List();
-  for (size_t i = 0; i < list.size(); ++i) {
-    request.AddHTTPHeaderField(AtomicString(list[i]->first),
-                               AtomicString(list[i]->second));
+  for (const auto& header : request_->HeaderList()->List()) {
+    request.AddHTTPHeaderField(AtomicString(header.first),
+                               AtomicString(header.second));
   }
 
   if (request_->Method() != HTTPNames::GET &&