Replace FX_FLOAT with underlying float type.

Change-Id: I158b7d80b0ec28b742a9f2d5a96f3dde7fb3ab56
Reviewed-on: https://pdfium-review.googlesource.com/3031
Commit-Queue: dsinclair <dsinclair@chromium.org>
Reviewed-by: Tom Sepez <tsepez@chromium.org>
Reviewed-by: Nicolás Peña <npm@chromium.org>

core/fpdfapi/page/cpdf_image.cpp

diff --git a/core/fpdfapi/page/cpdf_image.cpp b/core/fpdfapi/page/cpdf_image.cpp
index fea03c7..3de0511 100644
--- a/core/fpdfapi/page/cpdf_image.cpp
+++ b/core/fpdfapi/page/cpdf_image.cpp
@@ -298,7 +298,7 @@
     for (int32_t row = 0; row < BitmapHeight; row++) {
       src_offset = row * src_pitch;
       for (int32_t column = 0; column < BitmapWidth; column++) {
-        FX_FLOAT alpha = 1;
+        float alpha = 1;
         pDest[dest_offset] = (uint8_t)(src_buf[src_offset + 2] * alpha);
         pDest[dest_offset + 1] = (uint8_t)(src_buf[src_offset + 1] * alpha);
         pDest[dest_offset + 2] = (uint8_t)(src_buf[src_offset] * alpha);