Add stubs for switch and case output

BUG=angle:921

Change-Id: I58bd645a8d53ef5bad9b680e54c8948d50932fca
Reviewed-on: https://chromium-review.googlesource.com/251525
Reviewed-by: Zhenyao Mo <zmo@chromium.org>
Tested-by: Olli Etuaho <oetuaho@nvidia.com>
Reviewed-by: Jamie Madill <jmadill@chromium.org>
diff --git a/src/compiler/translator/OutputGLSLBase.cpp b/src/compiler/translator/OutputGLSLBase.cpp
index 175edbd..a3db2ee 100644
--- a/src/compiler/translator/OutputGLSLBase.cpp
+++ b/src/compiler/translator/OutputGLSLBase.cpp
@@ -638,6 +638,18 @@
     return false;
 }
 
+bool TOutputGLSLBase::visitSwitch(Visit, TIntermSwitch *)
+{
+    UNIMPLEMENTED();
+    return false;
+}
+
+bool TOutputGLSLBase::visitCase(Visit, TIntermCase *)
+{
+    UNIMPLEMENTED();
+    return false;
+}
+
 bool TOutputGLSLBase::visitAggregate(Visit visit, TIntermAggregate *node)
 {
     bool visitChildren = true;