--- a/dom/canvas/WebGLShaderValidator.cpp
+++ b/dom/canvas/WebGLShaderValidator.cpp
@@ -433,17 +433,17 @@ ShaderValidator::CalcNumSamplerUniforms(
 
     const std::vector<sh::Uniform>& uniforms = *sh::GetUniforms(mHandle);
 
     for (auto itr = uniforms.begin(); itr != uniforms.end(); ++itr) {
         GLenum type = itr->type;
         if (type == LOCAL_GL_SAMPLER_2D ||
             type == LOCAL_GL_SAMPLER_CUBE)
         {
-            accum += itr->arraySize;
+            accum += itr->getArraySizeProduct();
         }
     }
 
     return accum;
 }
 
 size_t
 ShaderValidator::NumAttributes() const