Rename FormData/FormDataBuilder to EncodedFormData/FormDataEncoder respectively.

Source/modules/fetch/BodyStreamBuffer.h

Index: Source/modules/fetch/BodyStreamBuffer.h
diff --git a/Source/modules/fetch/BodyStreamBuffer.h b/Source/modules/fetch/BodyStreamBuffer.h
index 2458798caff817c2c7a7c931ed0601205aae67b5..bff77a8ae92dd57cd49eb2a79a2b71decfdada65 100644
--- a/Source/modules/fetch/BodyStreamBuffer.h
+++ b/Source/modules/fetch/BodyStreamBuffer.h
@@ -19,8 +19,8 @@
 
 namespace blink {
 
+class EncodedFormData;
 class ExecutionContext;
-class FormData;
 
 // A BodyStreamBuffer constructed with a null handle is said to have null body.
 // One can observe if a buffer has null body by calling |hasBody| function.
@@ -38,7 +38,7 @@ public:
 
     // Callable only when not locked.
     PassRefPtr<BlobDataHandle> drainAsBlobDataHandle(FetchDataConsumerHandle::Reader::BlobSizePolicy);
-    PassRefPtr<FormData> drainAsFormData();
+    PassRefPtr<EncodedFormData> drainAsFormData();
 
     // Callable only when not locked. Returns a non-null handle even when
     // having null body.