Remove IgnorableExceptionState

third_party/WebKit/Source/bindings/core/v8/ExceptionState.h

Index: third_party/WebKit/Source/bindings/core/v8/ExceptionState.h
diff --git a/third_party/WebKit/Source/bindings/core/v8/ExceptionState.h b/third_party/WebKit/Source/bindings/core/v8/ExceptionState.h
index ba58a2bc625ecec23db3081477b5beef9e5fa40f..dd1f6ddbf151b5b10021dc151d384508bfdcc062 100644
--- a/third_party/WebKit/Source/bindings/core/v8/ExceptionState.h
+++ b/third_party/WebKit/Source/bindings/core/v8/ExceptionState.h
@@ -187,13 +187,13 @@ class CORE_EXPORT DummyExceptionStateForTesting final : public ExceptionState {
       clearException();
     }
   }
-
   void throwDOMException(ExceptionCode, const String& message) override;
   void throwTypeError(const String& message) override;
   void throwSecurityError(const String& sanitizedMessage,
                           const String& unsanitizedMessage) override;
   void throwRangeError(const String& message) override;
   void rethrowV8Exception(v8::Local<v8::Value>) override;
+  ExceptionState& returnThis() { return *this; }
 };
 
 }  // namespace blink