Fix build with Clang.

Clang's validation is a bit more thorough than GCC's or MSVC's and
picked up a few new errors and warnings. We missed a few default
cases in switches and used an improper type for default arguments.

BUG=angle:568

Change-Id: I34239c6c5c785ad1e62917fc37c3243f4c5b5f1b
Reviewed-on: https://chromium-review.googlesource.com/195472
Tested-by: Jamie Madill <jmadill@chromium.org>
Reviewed-by: Shannon Woods <shannonwoods@chromium.org>
Reviewed-by: Geoff Lang <geofflang@chromium.org>
diff --git a/src/compiler/translator/ParseContext.cpp b/src/compiler/translator/ParseContext.cpp
index 75c4938..8ff9d30 100644
--- a/src/compiler/translator/ParseContext.cpp
+++ b/src/compiler/translator/ParseContext.cpp
@@ -638,6 +638,8 @@
             error(line, "cannot be used with a structure", getQualifierString(pType.qualifier));
             return true;
         }
+
+      default: break;
     }
 
     if (pType.qualifier != EvqUniform && samplerErrorCheck(line, pType, "samplers must be uniform"))