Clean up specifying colors and texture scale in MipmapTest

src/tests/test_utils/ANGLETest.cpp

@@ -20,6 +20,7 @@ const GLColor GLColor::green = GLColor(0u, 255u, 0u, 255u);
 const GLColor GLColor::blue  = GLColor(0u, 0u, 255u, 255u);
 const GLColor GLColor::cyan  = GLColor(0u, 255u, 255u, 255u);
 const GLColor GLColor::black = GLColor(0u, 0u, 0u, 255u);
+const GLColor GLColor::white = GLColor(255u, 255u, 255u, 255u);
 
 namespace
 {

src/tests/test_utils/ANGLETest.h

@@ -58,6 +58,7 @@ struct GLColor
     static const GLColor blue;
     static const GLColor cyan;
     static const GLColor black;
+    static const GLColor white;
 };
 
 // Useful to cast any type to GLubyte.
@@ -72,18 +73,6 @@ bool operator==(const GLColor &a, const GLColor &b);
 std::ostream &operator<<(std::ostream &ostream, const GLColor &color);
 GLColor ReadColor(GLint x, GLint y);
 
-template <typename T>
-void FillWithRGBA(size_t pixelCount, T red, T green, T blue, T alpha, T *outArray)
-{
-    for (size_t i = 0u; i < pixelCount; ++i)
-    {
-        outArray[i * 4u]      = red;
-        outArray[i * 4u + 1u] = green;
-        outArray[i * 4u + 2u] = blue;
-        outArray[i * 4u + 3u] = alpha;
-    }
-}
-
 }  // namespace angle
 
 #define EXPECT_PIXEL_EQ(x, y, r, g, b, a) \