ES31: Validate fragment shader outputs

This allows to validate fragment shader outputs for
shader version #300 and newer.

Change-Id: I21b21ebb357eab61e36c080c328291ed20b8eb8f
Reviewed-on: https://chromium-review.googlesource.com/497749
Reviewed-by: Geoff Lang <geofflang@chromium.org>
Reviewed-by: Jamie Madill <jmadill@chromium.org>
Commit-Queue: Geoff Lang <geofflang@chromium.org>
Commit-Queue: Jamie Madill <jmadill@chromium.org>
diff --git a/src/compiler/translator/Compiler.cpp b/src/compiler/translator/Compiler.cpp
index 51398f5..2c93aa7 100644
--- a/src/compiler/translator/Compiler.cpp
+++ b/src/compiler/translator/Compiler.cpp
@@ -362,7 +362,7 @@
         if (success)
             PruneEmptyDeclarations(root);
 
-        if (success && shaderVersion == 300 && shaderType == GL_FRAGMENT_SHADER)
+        if (success && shaderVersion >= 300 && shaderType == GL_FRAGMENT_SHADER)
             success = validateOutputs(root);
 
         if (success && shouldRunLoopAndIndexingValidation(compileOptions))