Oilpan: Build fix after r201851

Source/modules/webgl/WebGL2RenderingContextBase.cpp

Index: Source/modules/webgl/WebGL2RenderingContextBase.cpp
diff --git a/Source/modules/webgl/WebGL2RenderingContextBase.cpp b/Source/modules/webgl/WebGL2RenderingContextBase.cpp
index 695e09ad88afecff6cbfc5cef105436d19d8660e..f72be87889ef8d03528d474c29b592bbdd3859fd 100644
--- a/Source/modules/webgl/WebGL2RenderingContextBase.cpp
+++ b/Source/modules/webgl/WebGL2RenderingContextBase.cpp
@@ -2583,6 +2583,8 @@ DEFINE_TRACE(WebGL2RenderingContextBase)
     visitor->trace(m_boundPixelUnpackBuffer);
     visitor->trace(m_boundTransformFeedbackBuffer);
     visitor->trace(m_boundUniformBuffer);
+    visitor->trace(m_boundIndexedTransformFeedbackBuffers);
+    visitor->trace(m_boundIndexedUniformBuffers);
     visitor->trace(m_currentBooleanOcclusionQuery);
     visitor->trace(m_currentTransformFeedbackPrimitivesWrittenQuery);
     visitor->trace(m_samplerUnits);