[Fetch API] Streaming error should be reported as a TypeError

When the browser encounters an error while reading a response body, it should
error the body stream with a TypeError.

BUG=656601

Review-Url: https://codereview.chromium.org/2439673002
Cr-Commit-Position: refs/heads/master@{#427052}

third_party/WebKit/LayoutTests/http/tests/fetch/script-tests/body-mixin.js

@@ -295,4 +295,12 @@ promise_test(t => {
       });
   }, 'Locked => text');
 
+promise_test(t => {
+    return fetch('/fetch/resources/slow-failure.cgi').then(response => {
+        return response.text().then(unreached_fulfillment(t), e => {
+            assert_equals(e.name, 'TypeError');
+          });
+      });
+  }, 'streaming error');
+
 done();

third_party/WebKit/LayoutTests/http/tests/fetch/script-tests/stream-reader.js

@@ -96,4 +96,15 @@ promise_test(function(t) {
       });
   }, 'Cancelling stream should not affect cloned one.');
 
+promise_test(t => {
+    let reader;
+    return fetch('/fetch/resources/slow-failure.cgi').then(res => {
+        reader = res.body.getReader();
+        return readableStreamToArray(res.body, reader);
+      }).then(unreached_fulfillment(t), e => {
+        reader.releaseLock();
+        assert_equals(e.name, 'TypeError');
+      });
+  }, 'Streaming error should be reported as a TypeError.');
+
 done();

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

@@ -6,6 +6,7 @@
 
 #include "bindings/core/v8/ScriptState.h"
 #include "bindings/core/v8/V8HiddenValue.h"
+#include "bindings/core/v8/V8ThrowException.h"
 #include "core/dom/DOMArrayBuffer.h"
 #include "core/dom/DOMTypedArray.h"
 #include "core/dom/ExceptionCode.h"
@@ -285,7 +286,11 @@ void BodyStreamBuffer::close() {
 }
 
 void BodyStreamBuffer::error() {
-  controller()->error(DOMException::create(NetworkError, "network error"));
+  {
+    ScriptState::Scope scope(m_scriptState.get());
+    controller()->error(V8ThrowException::createTypeError(
+        m_scriptState->isolate(), "network error"));
+  }
   cancelConsumer();
 }