Change BodyStreamBuffer to be FetchDataConsumerHandle-based and enable backpressure in Fetch API

Source/modules/fetch/Request.cpp

Index: Source/modules/fetch/Request.cpp
diff --git a/Source/modules/fetch/Request.cpp b/Source/modules/fetch/Request.cpp
index 82e6f5ad415045af0344498b0e441dcafa50d56b..01f1c607fa3ceb1bc1b228581fd04fe927ec90a0 100644
--- a/Source/modules/fetch/Request.cpp
+++ b/Source/modules/fetch/Request.cpp
@@ -74,7 +74,7 @@ Request* Request::createRequestWithRequestOrString(ScriptState* scriptState, Req
             // creating a draining stream.
             // TODO(yhirano): Fix this once Request.body is introduced.
             OwnPtr<BlobData> blobData = BlobData::create();
-            blobData->setContentType(inputRequest->blobDataHandle()->type());
+            blobData->setContentType(inputRequest->m_request->blobDataHandle()->type());
             temporaryBody = BlobDataHandle::create(blobData.release(), 0);
         } else {
             temporaryBody = inputRequest->m_request->blobDataHandle();
@@ -320,7 +320,7 @@ Request* Request::create(ExecutionContext* context, const WebServiceWorkerReques
 
 Request::Request(ExecutionContext* context, const WebServiceWorkerRequest& webRequest)
     : Body(context)
-    , m_request(FetchRequestData::create(webRequest))
+    , m_request(FetchRequestData::create(context, webRequest))
     , m_headers(Headers::create(m_request->headerList()))
 {
     m_headers->setGuard(Headers::RequestGuard);
@@ -472,16 +472,16 @@ Request* Request::clone(ExceptionState& exceptionState) const
         return nullptr;
     }
 
-    FetchRequestData* request = m_request->clone();
-    if (blobDataHandle() && isBodyConsumed()) {
+    FetchRequestData* request = m_request->clone(executionContext());
+    if (m_request->blobDataHandle() && isBodyConsumed()) {
         // Currently the only methods that can consume body data without
         // setting 'body passed' flag consume entire body (e.g. text()). Thus
         // we can set an empty blob to the new request instead of creating a
         // draining stream.
         // TODO(yhirano): Fix this once Request.body is introduced.
         OwnPtr<BlobData> blobData = BlobData::create();
-        blobData->setContentType(blobDataHandle()->type());
-        request->setBlobDataHandle(BlobDataHandle::create(blobData.release(), 0));
+        blobData->setContentType(m_request->blobDataHandle()->type());
+        request->setBlobDataHandle(executionContext(), BlobDataHandle::create(blobData.release(), 0));
     }
 
     Headers* headers = Headers::create(request->headerList());
@@ -495,7 +495,7 @@ FetchRequestData* Request::passRequestData()
 {
     ASSERT(!bodyUsed());
     lockBody(PassBody);
-    return m_request->pass();
+    return m_request->pass(executionContext());
 }
 
 void Request::populateWebServiceWorkerRequest(WebServiceWorkerRequest& webRequest) const
@@ -518,8 +518,8 @@ void Request::populateWebServiceWorkerRequest(WebServiceWorkerRequest& webReques
 
 void Request::setBodyBlobHandle(PassRefPtr<BlobDataHandle> blobDataHandle)
 {
-    m_request->setBlobDataHandle(blobDataHandle);
-    setBody(m_request->blobDataHandle());
+    m_request->setBlobDataHandle(executionContext(), blobDataHandle);
+    setBody(m_request->buffer());
 }
 
 void Request::clearHeaderList()
@@ -527,15 +527,9 @@ void Request::clearHeaderList()
     m_request->headerList()->clearList();
 }
 
-PassRefPtr<BlobDataHandle> Request::blobDataHandle() const
+BodyStreamBuffer2* Request::buffer() const
 {
-    return m_request->blobDataHandle();
-}
-
-BodyStreamBuffer* Request::buffer() const
-{
-    // We don't support BodyStreamBuffer for Request yet.
-    return nullptr;
+    return m_request->buffer();
 }
 
 String Request::mimeType() const