Literal AtomicString construction can rely on strlen optimization.

third_party/WebKit/Source/modules/credentialmanager/PasswordCredential.cpp

 // Copyright 2014 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 "modules/credentialmanager/PasswordCredential.h"
 
 #include "bindings/core/v8/Dictionary.h"
 #include "bindings/core/v8/ExceptionState.h"
 #include "core/dom/ExecutionContext.h"
 #include "core/dom/URLSearchParams.h"
@@ skipping 51 matching lines @@
         URLSearchParams* params = URLSearchParams::create(URLSearchParamsInit());
         URLSearchParams* additionalData = m_additionalData.getAsURLSearchParams();
         for (const auto& param : additionalData->params()) {
             const String& name = param.first;
             if (name != idName() && name != passwordName())
                 params->append(name, param.second);
         }
         params->append(idName(), id());
         params->append(passwordName(), password());
 
-        contentType = AtomicString("application/x-www-form-urlencoded;charset=UTF-8", AtomicString::ConstructFromLiteral);
+        contentType = AtomicString("application/x-www-form-urlencoded;charset=UTF-8");
 
         return params->encodeFormData();
     }
 
     // Otherwise, we'll build a multipart response.
     FormData* formData = FormData::create(nullptr);
     if (m_additionalData.isFormData()) {
         FormData* additionalData = m_additionalData.getAsFormData();
         for (const FormData::Entry* entry : additionalData->entries()) {
             const String& name = formData->decode(entry->name());
             if (name == idName() || name == passwordName())
                 continue;
 
             if (entry->blob())
                 formData->append(name, entry->blob(), entry->filename());
             else
                 formData->append(name, formData->decode(entry->value()));
         }
     }
     formData->append(idName(), id());
     formData->append(passwordName(), password());
 
     RefPtr<EncodedFormData> encodedData = formData->encodeMultiPartFormData();
-    contentType = AtomicString("multipart/form-data; boundary=", AtomicString::ConstructFromLiteral) + encodedData->boundary().data();
+    contentType = AtomicString("multipart/form-data; boundary=") + encodedData->boundary().data();
     return encodedData.release();
 }
 
 const String& PasswordCredential::password() const
 {
     return static_cast<PlatformPasswordCredential*>(m_platformCredential.get())->password();
 }
 
 DEFINE_TRACE(PasswordCredential)
 {
     Credential::trace(visitor);
     visitor->trace(m_additionalData);
 }
 
 } // namespace blink