Length returned from glGetUniform*RobustANGLE should be in values, not bytes.

src/libANGLE/validationES.cpp

@@ -3463,8 +3463,7 @@ static bool ValidateSizedGetUniform(Context *context,
 
     if (length)
     {
-        // Cast is safe because of comparison to bufSize.
-        *length = static_cast<GLsizei>(requiredBytes);
+        *length = VariableComponentCount(uniform.type);
     }
 
     return true;