message: Fix 12x overallocation of memory in MorphTargetBuffer.
  I noticed this while helping someone at Google understand our new API.
diff: @@ -77,7 +77,7 @@ inline size_t getSize(size_t vertexCount) noexcept;
  template<>
  inline size_t getSize<VertexAttribute::POSITION>(size_t vertexCount) noexcept {
  - const size_t stride = getWidth(vertexCount) * sizeof(float3);
  + const size_t stride = getWidth(vertexCount);
  const size_t height = getHeight(vertexCount);
  return Texture::PixelBufferDescriptor::computeDataSize(
  Texture::PixelBufferDescriptor::PixelDataFormat::RGBA,
  @@ -87,7 +87,7 @@ inline size_t getSize<VertexAttribute::POSITION>(size_t vertexCount) noexcept {
  template<>
  inline size_t getSize<VertexAttribute::TANGENTS>(size_t vertexCount) noexcept {
  - const size_t stride = getWidth(vertexCount) * sizeof(short4);
  + const size_t stride = getWidth(vertexCount);
  const size_t height = getHeight(vertexCount);
  return Texture::PixelBufferDescriptor::computeDataSize(
  Texture::PixelBufferDescriptor::PixelDataFormat::RGBA_INTEGER,
  