[Fetch API] Implement Request.formData and Response.formData.

third_party/WebKit/Source/modules/fetch/BodyStreamBuffer.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/fetch/BodyStreamBuffer.h"
 
 #include <memory>
 #include "bindings/core/v8/ExceptionState.h"
 #include "bindings/core/v8/ScriptState.h"
 #include "bindings/core/v8/V8PrivateProperty.h"
@@ skipping 30 matching lines @@
       PassRefPtr<BlobDataHandle> blob_data_handle) override {
     buffer_->EndLoading();
     client_->DidFetchDataLoadedBlobHandle(std::move(blob_data_handle));
   }
 
   void DidFetchDataLoadedArrayBuffer(DOMArrayBuffer* array_buffer) override {
     buffer_->EndLoading();
     client_->DidFetchDataLoadedArrayBuffer(array_buffer);
   }
 
+  void DidFetchDataLoadedFormData(FormData* form_data) override {
+    buffer_->EndLoading();
+    client_->DidFetchDataLoadedFormData(form_data);
+  }
+
   void DidFetchDataLoadedString(const String& string) override {
     buffer_->EndLoading();
     client_->DidFetchDataLoadedString(string);
   }
 
   void DidFetchDataLoadedDataPipe() override {
     buffer_->EndLoading();
     client_->DidFetchDataLoadedDataPipe();
   }
 
@@ skipping 216 matching lines @@
   }
 
   ScriptState::Scope scope(script_state_.Get());
   NonThrowableExceptionState exception_state;
   ScriptValue reader = ReadableStreamOperations::GetReader(
       script_state_.Get(), Stream(), exception_state);
   ReadableStreamOperations::DefaultReaderRead(script_state_.Get(), reader);
 }
 
 void BodyStreamBuffer::Close() {
-  Controller()->Close();
+  if (Controller())

[yhirano, 2017/05/10 05:59:36]

Can you tell me why we need this change?

[e_hakkinen, 2017/05/11 11:01:51]

Without this change, external/wpt/fetch/api/response/response-consume.html test
cases "from stream without correct multipart type to formData (error case)" and
"from stream without correct urlencoded type to formData (error case)" will
trigger null pointer exception here.

formData is different from, say, json because formData can trigger an error path
also before bytes are actually read (if content type is not valid) whereas json
can trigger an error path only after bytes are read and are being parsed.

[yhirano, 2017/05/12 11:54:12]

Hmm, I think calling CloseAndLockAndDisturb in such a case is not correct... See
the comment in Body::formData().

+    Controller()->Close();
   CancelConsumer();
 }
 
 void BodyStreamBuffer::GetError() {
   {
     ScriptState::Scope scope(script_state_.Get());
     Controller()->GetError(V8ThrowException::CreateTypeError(
         script_state_->GetIsolate(), "network error"));
   }
   CancelConsumer();
@@ skipping 91 matching lines @@
   }
   if (is_errored)
     return BytesConsumer::CreateErrored(BytesConsumer::Error("error"));
 
   DCHECK(consumer);
   consumer->ClearClient();
   return consumer;
 }
 
 }  // namespace blink