[Fetch API] Fix a memory leak with a Response constructed with a ReadableStream

third_party/WebKit/Source/modules/fetch/Response.cpp

Index: third_party/WebKit/Source/modules/fetch/Response.cpp
diff --git a/third_party/WebKit/Source/modules/fetch/Response.cpp b/third_party/WebKit/Source/modules/fetch/Response.cpp
index 478426227a827e71def320de9bc3118152d37998..0aabf677a440bc6ea4c4527da065ed72fea45ac9 100644
--- a/third_party/WebKit/Source/modules/fetch/Response.cpp
+++ b/third_party/WebKit/Source/modules/fetch/Response.cpp
@@ -14,11 +14,13 @@
 #include "bindings/core/v8/V8Binding.h"
 #include "bindings/core/v8/V8Blob.h"
 #include "bindings/core/v8/V8FormData.h"
+#include "bindings/core/v8/V8HiddenValue.h"
 #include "core/dom/DOMArrayBuffer.h"
 #include "core/dom/DOMArrayBufferView.h"
 #include "core/fileapi/Blob.h"
 #include "core/html/FormData.h"
 #include "modules/fetch/BodyStreamBuffer.h"
+#include "modules/fetch/DataConsumerHandleUtil.h"
 #include "modules/fetch/FetchBlobDataConsumerHandle.h"
 #include "modules/fetch/FetchFormDataConsumerHandle.h"
 #include "modules/fetch/ReadableStreamDataConsumerHandle.h"
@@ -112,6 +114,7 @@ Response* Response::create(ScriptState* scriptState, ExceptionState& exceptionSt
 Response* Response::create(ScriptState* scriptState, ScriptValue bodyValue, const Dictionary& init, ExceptionState& exceptionState)
 {
     v8::Local<v8::Value> body = bodyValue.v8Value();
+    ScriptValue reader;
     v8::Isolate* isolate = scriptState->isolate();
     ExecutionContext* executionContext = scriptState->executionContext();
 
@@ -132,7 +135,14 @@ Response* Response::create(ScriptState* scriptState, ScriptValue bodyValue, cons
         contentType = AtomicString("multipart/form-data; boundary=", AtomicString::ConstructFromLiteral) + formData->boundary().data();
         bodyHandle = FetchFormDataConsumerHandle::create(executionContext, formData.release());
     } else if (RuntimeEnabledFeatures::responseConstructedWithReadableStreamEnabled() && ReadableStreamOperations::isReadableStream(scriptState, body)) {
-        bodyHandle = ReadableStreamDataConsumerHandle::create(scriptState, body);
+        reader = ReadableStreamOperations::getReader(scriptState, body, exceptionState);
+        if (exceptionState.hadException()) {
+            reader = ScriptValue();
+            bodyHandle = createFetchDataConsumerHandleFromWebHandle(createUnexpectedErrorDataConsumerHandle());
+            exceptionState.clearException();
+        } else {
+            bodyHandle = ReadableStreamDataConsumerHandle::create(scriptState, reader.v8Value().As<v8::Object>());

[bashi, 2016/01/06 05:39:17]

just to clarify: reader.v8Value() is always an Object?

[yhirano, 2016/01/26 05:09:32]

Deleted, but yes, ReadableStreamOperations::isReadableStream checks it.

+        }
     } else {
         String string = toUSVString(isolate, body, exceptionState);
         if (exceptionState.hadException())
@@ -141,7 +151,17 @@ Response* Response::create(ScriptState* scriptState, ScriptValue bodyValue, cons
         contentType = "text/plain;charset=UTF-8";
     }
     // TODO(yhirano): Add the URLSearchParams case.
-    return create(executionContext, bodyHandle.release(), contentType, ResponseInit(init, exceptionState), exceptionState);
+    Response* response = create(executionContext, bodyHandle.release(), contentType, ResponseInit(init, exceptionState), exceptionState);
+    if (!reader.isEmpty()) {
+        // Add a hidden reference so that the weak persistent in the
+        // ReadableStreamDataConsumerHandle will be valid as long as the
+        // the Response is valid.

[haraken, 2016/01/06 05:49:06]

the the

[yhirano, 2016/01/26 05:09:32]

Done.

+        v8::Local<v8::Value> wrapper = toV8(response, scriptState->context()->Global(), scriptState->isolate());
+        ASSERT(!wrapper.IsEmpty());

[haraken, 2016/01/06 05:49:06]

toV8 can return an empty handle.

[yhirano, 2016/01/26 05:09:32]

Done.

+        ASSERT(wrapper->IsObject());
+        V8HiddenValue::setHiddenValue(scriptState, wrapper.As<v8::Object>(), V8HiddenValue::readableStreamReaderInResponse(scriptState->isolate()), reader.v8Value());
+    }
+    return response;
 }
 
 Response* Response::create(ExecutionContext* context, PassOwnPtr<FetchDataConsumerHandle> bodyHandle, const String& contentType, const ResponseInit& init, ExceptionState& exceptionState)