[Fetch] Body consume function should not set bodyUsed flag.

Source/modules/fetch/Body.cpp

Index: Source/modules/fetch/Body.cpp
diff --git a/Source/modules/fetch/Body.cpp b/Source/modules/fetch/Body.cpp
index f80644561fcbefd072de728387f62a7356355637..37a33350f94458f6b112c22eedea308dd485806b 100644
--- a/Source/modules/fetch/Body.cpp
+++ b/Source/modules/fetch/Body.cpp
@@ -273,19 +273,54 @@ ScriptPromise Body::readAsync(ScriptState* scriptState, ResponseType type)
     if (!executionContext)
         return ScriptPromise();
 
-    lockBody(PassBody);
+    lockBody();
     m_responseType = type;
 
     ASSERT(!m_resolver);
     m_resolver = ScriptPromiseResolver::create(scriptState);
     ScriptPromise promise = m_resolver->promise();
 
-    if (streamAccessed()) {
-        m_streamSource->createDrainingStream()->readAllAndCreateBlobHandle(mimeType(), new BlobHandleReceiver(this));
-    } else if (buffer()) {
-        buffer()->readAllAndCreateBlobHandle(mimeType(), new BlobHandleReceiver(this));
+    if (m_stream->stateInternal() == ReadableStream::Closed) {
+        // We resolve the resolver manually in order not to use member
+        // variables.
+        switch (m_responseType) {
+        case ResponseAsArrayBuffer:
+            m_resolver->resolve(DOMArrayBuffer::create(nullptr, 0));
+            break;
+        case ResponseAsBlob: {
+            OwnPtr<BlobData> blobData = BlobData::create();
+            blobData->setContentType(mimeType());
+            m_resolver->resolve(Blob::create(BlobDataHandle::create(blobData.release(), 0)));
+            break;
+        }
+        case ResponseAsText:
+            m_resolver->resolve(String());
+            break;
+        case ResponseAsFormData:
+            // TODO(yhirano): Implement this.
+            ASSERT_NOT_REACHED();
+            break;
+        case ResponseAsJSON: {
+            ScriptState::Scope scope(m_resolver->scriptState());
+            m_resolver->reject(V8ThrowException::createSyntaxError(m_resolver->scriptState()->isolate(), "Unexpected end of input"));
+            break;
+        }
+        case ResponseUnknown:
+            ASSERT_NOT_REACHED();
+            break;
+        }
+        m_resolver.clear();
+    } else if (m_stream->stateInternal() == ReadableStream::Errored) {
+        m_resolver->reject(m_stream->storedException());
+        m_resolver.clear();
     } else {

[horo, 2015/04/01 12:04:54]

nit: Why don't you continue using "else if"?

[yhirano, 2015/04/01 12:11:55]

Done.

-        readAsyncFromBlob(blobDataHandle());
+        if (isBodyConsumed()) {
+            m_streamSource->createDrainingStream()->readAllAndCreateBlobHandle(mimeType(), new BlobHandleReceiver(this));
+        } else if (buffer()) {
+            buffer()->readAllAndCreateBlobHandle(mimeType(), new BlobHandleReceiver(this));
+        } else {
+            readAsyncFromBlob(blobDataHandle());
+        }
     }
     return promise;
 }
@@ -384,9 +419,22 @@ void Body::lockBody(LockBodyOption option)
     ASSERT(!exceptionState.hadException());
 }
 
-bool Body::streamAccessed() const
+bool Body::isBodyConsumed() const
 {
-    return m_streamSource->state() != m_streamSource->Initial;
+    if (m_streamSource->state() != m_streamSource->Initial) {
+        // Some data is pulled from the source.
+        return true;
+    }
+    if (m_stream->stateInternal() == ReadableStream::Closed) {
+        // Return true if the blob handle is originally not empty.
+        RefPtr<BlobDataHandle> handle = blobDataHandle();
+        return handle && handle->size();
+    }
+    if (m_stream->stateInternal() == ReadableStream::Errored) {
+        // The stream is errored. That means an effort to read data was made.
+        return true;
+    }
+    return false;
 }
 
 void Body::refreshBody()