Consolidate read-only exception throwing for SVG*TearOffs

third_party/WebKit/Source/core/svg/properties/SVGPropertyTearOff.cpp

Index: third_party/WebKit/Source/core/svg/properties/SVGPropertyTearOff.cpp
diff --git a/third_party/WebKit/Source/core/svg/properties/SVGPropertyTearOff.cpp b/third_party/WebKit/Source/core/svg/properties/SVGPropertyTearOff.cpp
index de0a6cb48cc18a9bdea36e1f3df9bc51e907996d..327c1900f984f014ed1ae0cd0af0639f7a9b420e 100644
--- a/third_party/WebKit/Source/core/svg/properties/SVGPropertyTearOff.cpp
+++ b/third_party/WebKit/Source/core/svg/properties/SVGPropertyTearOff.cpp
@@ -30,16 +30,24 @@
 
 #include "core/svg/properties/SVGPropertyTearOff.h"
 
+#include "bindings/core/v8/ExceptionMessages.h"
+#include "bindings/core/v8/ExceptionState.h"
+#include "core/dom/ExceptionCode.h"
 #include "core/svg/SVGElement.h"
 
 namespace blink {
 
+void SVGPropertyTearOffBase::throwReadOnly(ExceptionState& exceptionState)
+{
+    exceptionState.throwDOMException(NoModificationAllowedError, ExceptionMessages::readOnly());
+}
+
 void SVGPropertyTearOffBase::commitChange()
 {
-    ASSERT(!isImmutable());
+    DCHECK(!isImmutable());
     if (!contextElement() || isAnimVal())
         return;
-    ASSERT(m_attributeName != QualifiedName::null());
+    DCHECK(m_attributeName != QualifiedName::null());
     contextElement()->invalidateSVGAttributes();
     contextElement()->svgAttributeBaseValChanged(m_attributeName);
 }