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 37ad99a8621ae4bf4cc5cddb74b97db9a3f11748..f32d4c9efc7d5be8eb28494bed2c62e2328c176c 100644
--- a/third_party/WebKit/Source/modules/fetch/FetchManager.cpp
+++ b/third_party/WebKit/Source/modules/fetch/FetchManager.cpp
@@ -726,11 +726,9 @@ void FetchManager::Loader::performHTTPFetch(bool corsFlag,
   request.setHTTPMethod(m_request->method());
   request.setFetchRequestMode(m_request->mode());
   request.setFetchCredentialsMode(m_request->credentials());
-  const Vector<std::unique_ptr<FetchHeaderList::Header>>& list =
-      m_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 : m_request->headerList()->list()) {
+    request.addHTTPHeaderField(AtomicString(header.first),
+                               AtomicString(header.second));
   }
 
   if (m_request->method() != HTTPNames::GET &&