[Service Workers] DCHECK from WebServiceWorkerResponse::visitHTTPHeaderFields.

content/renderer/service_worker/service_worker_type_util.cc

 // Copyright 2015 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "content/renderer/service_worker/service_worker_type_util.h"
 
 #include <string>
 
 #include "base/memory/scoped_ptr.h"
 #include "base/strings/utf_string_conversions.h"
 #include "content/common/service_worker/service_worker_types.h"
 #include "third_party/WebKit/public/platform/WebHTTPHeaderVisitor.h"
 #include "third_party/WebKit/public/platform/WebString.h"
 #include "third_party/WebKit/public/platform/modules/serviceworker/WebServiceWorkerRequest.h"
 #include "third_party/WebKit/public/platform/modules/serviceworker/WebServiceWorkerResponse.h"
 
 namespace content {
 
 namespace {
 
 class HeaderVisitor : public blink::WebHTTPHeaderVisitor {
  public:
   HeaderVisitor(ServiceWorkerHeaderMap* headers) : headers_(headers) {}
   virtual ~HeaderVisitor() {}
 
   void visitHeader(const blink::WebString& name,
                    const blink::WebString& value) override {
-    const std::string header_name =
-        base::UTF16ToASCII(base::StringPiece16(name));
-    const std::string header_value =
-        base::UTF16ToASCII(base::StringPiece16(value));
+    // Headers are ISO Latin 1.
+    const std::string& header_name = name.latin1();
+    const std::string& header_value = value.latin1();
     CHECK(header_name.find('\0') == std::string::npos);
     CHECK(header_value.find('\0') == std::string::npos);
     headers_->insert(ServiceWorkerHeaderMap::value_type(
         header_name, header_value));
   }
 
  private:
   ServiceWorkerHeaderMap* headers_;
 };
 
@@ skipping 13 matching lines @@
 
 void GetServiceWorkerHeaderMapFromWebResponse(
     const blink::WebServiceWorkerResponse& web_response,
     ServiceWorkerHeaderMap* headers) {
   DCHECK(headers);
   DCHECK(!headers->size());
   web_response.visitHTTPHeaderFields(MakeHeaderVisitor(headers).get());
 }
 
 }  // namespace content