Literal AtomicString construction can rely on strlen optimization.

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

 // 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 "modules/fetch/FetchFormDataConsumerHandle.h"
 
 #include "modules/fetch/DataConsumerHandleUtil.h"
 #include "modules/fetch/FetchBlobDataConsumerHandle.h"
 #include "wtf/ThreadSafeRefCounted.h"
 #include "wtf/ThreadingPrimitives.h"
@@ skipping 247 matching lines @@
                 if (element.m_optionalBlobDataHandle)
                     blobData->appendBlob(element.m_optionalBlobDataHandle, 0, element.m_optionalBlobDataHandle->size());
                 break;
             case FormDataElement::encodedFileSystemURL:
                 blobData->appendFileSystemURL(element.m_fileSystemURL, element.m_fileStart, element.m_fileLength, element.m_expectedFileModificationTime);
                 break;
             }
         }
         // Here we handle body->boundary() as a C-style string. See
         // FormDataEncoder::generateUniqueBoundaryString.
-        blobData->setContentType(AtomicString("multipart/form-data; boundary=", AtomicString::ConstructFromLiteral) + body->boundary().data());
+        blobData->setContentType(AtomicString("multipart/form-data; boundary=") + body->boundary().data());
         auto size = blobData->length();
         if (factory) {
             // For testing
             m_handle = FetchBlobDataConsumerHandle::create(executionContext, BlobDataHandle::create(blobData.release(), size), factory);
         } else {
             m_handle = FetchBlobDataConsumerHandle::create(executionContext, BlobDataHandle::create(blobData.release(), size));
         }
         // It is important to initialize |m_formData| here, because even
         // read-only operations may make the form data unsharable with implicit
         // ref-counting.
@@ skipping 50 matching lines @@
     }
 }
 FetchFormDataConsumerHandle::~FetchFormDataConsumerHandle() {}
 
 FetchDataConsumerHandle::Reader* FetchFormDataConsumerHandle::obtainReaderInternal(Client* client)
 {
     return m_context->obtainReader(client).leakPtr();
 }
 
 } // namespace blink