Merge "Update shader declarations to use 'uniform' instead of 'in'" into sc-dev

BlurFilter::BlurFilter() {

    SkString blurString(R"(

        in shader input;

        uniform shader input;

        uniform float2 in_blurOffset;

        uniform float2 in_maxSizeXY;

    mBlurEffect = std::move(blurEffect);

    SkString mixString(R"(

        in shader blurredInput;

        in shader originalInput;

        uniform shader blurredInput;

        uniform shader originalInput;

        uniform float mixFactor;

        half4 main(float2 xy) {