--- a/dom/canvas/WebGLTexture.cpp
+++ b/dom/canvas/WebGLTexture.cpp
@@ -182,25 +182,16 @@ WebGLTexture::SetImageInfosAtLevel(uint3
 {
     for (uint8_t i = 0; i < mFaceCount; i++) {
         ImageInfoAtFace(i, level) = newInfo;
     }
 
     InvalidateResolveCache();
 }
 
-static inline uint32_t
-MaxMipmapLevelsForSize(const WebGLTexture::ImageInfo& info)
-{
-    auto size = std::max(std::max(info.mWidth, info.mHeight), info.mDepth);
-
-    // Find floor(log2(maxsize)) + 1. (ES 3.0.4, 3.8 - Mipmapping).
-    return mozilla::FloorLog2(size) + 1;
-}
-
 bool
 WebGLTexture::IsMipmapComplete() const
 {
     MOZ_ASSERT(DoesMinFilterRequireMipmap());
     // GLES 3.0.4, p161
 
     const uint32_t maxLevel = MaxEffectiveMipmapLevel();