Implement FormData::isSafeToSendToAnotherThread()

Source/platform/network/FormData.h

Index: Source/platform/network/FormData.h
diff --git a/Source/platform/network/FormData.h b/Source/platform/network/FormData.h
index ecacf05cc6e40b41a1aae0049a57dfb83cdc87cc..14eb9866b98f1b14aeb3c7d7e0c66576bed9dc3f 100644
--- a/Source/platform/network/FormData.h
+++ b/Source/platform/network/FormData.h
@@ -40,6 +40,8 @@ public:
     explicit FormDataElement(const String& blobUUID, PassRefPtr<BlobDataHandle> optionalHandle) : m_type(encodedBlob), m_blobUUID(blobUUID), m_optionalBlobDataHandle(optionalHandle) { }
     FormDataElement(const KURL& fileSystemURL, long long start, long long length, double expectedFileModificationTime) : m_type(encodedFileSystemURL), m_fileSystemURL(fileSystemURL), m_fileStart(start), m_fileLength(length), m_expectedFileModificationTime(expectedFileModificationTime) { }
 
+    bool isSafeToSendToAnotherThread() const;
+
     enum Type {
         data,
         encodedFile,
@@ -132,6 +134,8 @@ public:
     // Size of the elements making up the FormData.
     unsigned long long sizeInBytes() const;
 
+    bool isSafeToSendToAnotherThread() const;
+
 private:
     FormData();
     FormData(const FormData&);