Revert of Streams: Remove isTerminating() calls

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

Index: third_party/WebKit/Source/modules/fetch/BodyStreamBuffer.cpp
diff --git a/third_party/WebKit/Source/modules/fetch/BodyStreamBuffer.cpp b/third_party/WebKit/Source/modules/fetch/BodyStreamBuffer.cpp
index 8c79a43b15ea5a52034bcff893a89695202e21cf..0da568020a8a300f9977abc4ffe4fa9681e78975 100644
--- a/third_party/WebKit/Source/modules/fetch/BodyStreamBuffer.cpp
+++ b/third_party/WebKit/Source/modules/fetch/BodyStreamBuffer.cpp
@@ -6,11 +6,13 @@
 
 #include "bindings/core/v8/ScriptState.h"
 #include "bindings/core/v8/V8HiddenValue.h"
+#include "bindings/core/v8/WorkerOrWorkletScriptController.h"
 #include "core/dom/DOMArrayBuffer.h"
 #include "core/dom/DOMTypedArray.h"
 #include "core/dom/ExceptionCode.h"
 #include "core/streams/ReadableStreamController.h"
 #include "core/streams/ReadableStreamOperations.h"
+#include "core/workers/WorkerGlobalScope.h"
 #include "modules/fetch/Body.h"
 #include "modules/fetch/BytesConsumerForDataConsumerHandle.h"
 #include "modules/fetch/DataConsumerHandleUtil.h"
@@ -22,6 +24,20 @@
 
 namespace blink {
 
+namespace {
+
+bool isTerminating(ScriptState* scriptState)
+{
+    ExecutionContext* executionContext = scriptState->getExecutionContext();
+    if (!executionContext)
+        return true;
+    if (!executionContext->isWorkerGlobalScope())
+        return false;
+    return toWorkerGlobalScope(executionContext)->scriptController()->isExecutionTerminating();
+}
+
+} // namespace
+
 class BodyStreamBuffer::LoaderClient final : public GarbageCollectedFinalized<LoaderClient>, public ActiveDOMObject, public FetchDataLoader::Client {
     WTF_MAKE_NONCOPYABLE(LoaderClient);
     USING_GARBAGE_COLLECTED_MIXIN(LoaderClient);
@@ -89,12 +105,28 @@
     , m_reader(m_handle->obtainFetchDataReader(this))
     , m_madeFromReadableStream(false)
 {
+    if (isTerminating(scriptState)) {
+        m_reader = nullptr;
+        m_handle = nullptr;
+        return;
+    }
     v8::Local<v8::Value> bodyValue = toV8(this, scriptState);
+    if (bodyValue.IsEmpty()) {
+        DCHECK(isTerminating(scriptState));
+        m_reader = nullptr;
+        m_handle = nullptr;
+        return;
+    }
     DCHECK(bodyValue->IsObject());
     v8::Local<v8::Object> body = bodyValue.As<v8::Object>();
 
     ScriptValue readableStream = ReadableStreamOperations::createReadableStream(
         scriptState, this, ReadableStreamOperations::createCountQueuingStrategy(scriptState, 0));
+    if (isTerminating(scriptState)) {
+        m_reader = nullptr;
+        m_handle = nullptr;
+        return;
+    }
     V8HiddenValue::setHiddenValue(scriptState, body, V8HiddenValue::internalBodyStream(scriptState->isolate()), readableStream.v8Value());
 }
 
@@ -104,7 +136,13 @@
     , m_madeFromReadableStream(true)
 {
     DCHECK(ReadableStreamOperations::isReadableStream(scriptState, stream));
+    if (isTerminating(scriptState))
+        return;
     v8::Local<v8::Value> bodyValue = toV8(this, scriptState);
+    if (bodyValue.IsEmpty()) {
+        DCHECK(isTerminating(scriptState));
+        return;
+    }
     DCHECK(bodyValue->IsObject());
     v8::Local<v8::Object> body = bodyValue.As<v8::Object>();
 
@@ -114,7 +152,13 @@
 ScriptValue BodyStreamBuffer::stream()
 {
     ScriptState::Scope scope(m_scriptState.get());
+    if (isTerminating(m_scriptState.get()))
+        return ScriptValue();
     v8::Local<v8::Value> bodyValue = toV8(this, m_scriptState.get());
+    if (bodyValue.IsEmpty()) {
+        DCHECK(isTerminating(m_scriptState.get()));
+        return ScriptValue();
+    }
     DCHECK(bodyValue->IsObject());
     v8::Local<v8::Object> body = bodyValue.As<v8::Object>();
     return ScriptValue(m_scriptState.get(), V8HiddenValue::getHiddenValue(m_scriptState.get(), body, V8HiddenValue::internalBodyStream(m_scriptState->isolate())));