Implement FormData::isSafeToSendToAnotherThread()

Source/platform/network/FormData.cpp

Index: Source/platform/network/FormData.cpp
diff --git a/Source/platform/network/FormData.cpp b/Source/platform/network/FormData.cpp
index 29c655aba4176a3236a04312d86fa7a0c43ca46a..c56f4c8f394813b1d5840345c16f6ede28e82ee9 100644
--- a/Source/platform/network/FormData.cpp
+++ b/Source/platform/network/FormData.cpp
@@ -29,6 +29,13 @@
 
 namespace blink {
 
+bool FormDataElement::isSafeToSendToAnotherThread() const
+{
+    return m_filename.isSafeToSendToAnotherThread()
+        && m_blobUUID.isSafeToSendToAnotherThread()
+        && m_fileSystemURL.isSafeToSendToAnotherThread();
+}
+
 inline FormData::FormData()
     : m_identifier(0)
     , m_containsPasswordData(false)
@@ -187,4 +194,15 @@ unsigned long long FormData::sizeInBytes() const
     return size;
 }
 
+bool FormData::isSafeToSendToAnotherThread() const
+{
+    if (!hasOneRef())
+        return false;
+    for (auto& element : m_elements) {
+        if (!element.isSafeToSendToAnotherThread())
+            return false;
+    }
+    return true;
+}
+
 } // namespace blink