[Fetch API] Abort fetching when the passed ScriptState is invalid.

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

Index: third_party/WebKit/Source/modules/fetch/GlobalFetch.cpp
diff --git a/third_party/WebKit/Source/modules/fetch/GlobalFetch.cpp b/third_party/WebKit/Source/modules/fetch/GlobalFetch.cpp
index bae556366045de25d0f4c6bf790e4cd5e7f39ca7..a4bdd715b4aee27eda21eecc871e944e426fea19 100644
--- a/third_party/WebKit/Source/modules/fetch/GlobalFetch.cpp
+++ b/third_party/WebKit/Source/modules/fetch/GlobalFetch.cpp
@@ -33,6 +33,11 @@ public:
 
     ScriptPromise fetch(ScriptState* scriptState, const RequestInfo& input, const Dictionary& init, ExceptionState& exceptionState) override
     {
+        if (!scriptState->contextIsValid()) {
+            // TODO(yhirano): Should this be moved to bindings?
+            exceptionState.throwTypeError("The global scope is shutting down.");
+            return ScriptPromise();
+        }
         if (m_fetchManager->isStopped()) {
             exceptionState.throwTypeError("The global scope is shutting down.");
             return ScriptPromise();