tdf#166339 vcl: Removed Windows skia text gamma patch

Reverts the following commit:

commit 1ad3f6b8d9
Date:   Wed Mar 18 12:10:29 2020 +0100

    (do not) use SK_GAMMA_APPLY_TO_A8 also for Skia text on Windows

    This is the Windows variant of the SK_GAMMA_APPLY_TO_A8 disabling,
    again I don't quite understand why we need to disable this,
    but with this patch Skia text rendering on Windows seems to be
    pixel-perfect when compared with the VCL gen backend.

The patch added by this commit disabled gamma correction for text
rendered by Skia under Windows. Disabling gamma-correct rendering causes
nasty artifacts, like fringing or text appearing as the wrong weight.

Change-Id: I9116712f47e22398259ecc93b165879f0cf29563
Reviewed-on: https://gerrit.libreoffice.org/c/core/+/187290
Tested-by: Jenkins
Reviewed-by: Jonathan Clark <jonathan@libreoffice.org>

external/skia/UnpackedTarball_skia.mk

@@ -21,7 +21,6 @@ skia_patches := \
     clang-attributes-warning.patch.1 \
     fontconfig-get-typeface.patch.1 \
     windows-do-not-modify-logfont.patch.0 \
-    windows-text-gamma.patch.0 \
     windows-force-unicode-api.patch.0 \
     fix-without-gl.patch.1 \
     windows-typeface-directwrite.patch.1 \

external/skia/windows-text-gamma.patch.0

@@ -1,72 +0,0 @@
---- ./src/ports/SkFontHost_win.cpp	2024-10-04 15:24:40.448100018 +0200
-+++ ./src/ports/SkFontHost_win.cpp	2024-10-04 15:26:22.284624363 +0200
-@@ -1149,18 +1149,24 @@
-         // since the caller may require A8 for maskfilters, we can't check for BW
-         // ... until we have the caller tell us that explicitly
-         const SkGdiRGB* src = (const SkGdiRGB*)bits;
-+#if defined(SK_GAMMA_APPLY_TO_A8)
-         if (fPreBlend.isApplicable()) {
-             RGBToA8<true>(src, srcRB, glyph, imageBuffer, fPreBlend.fG);
--        } else {
-+        } else
-+#endif
-+        {
-             RGBToA8<false>(src, srcRB, glyph, imageBuffer, fPreBlend.fG);
-         }
-     } else {    // LCD16
-         const SkGdiRGB* src = (const SkGdiRGB*)bits;
-         SkASSERT(SkMask::kLCD16_Format == glyph.maskFormat());
-+#if defined(SK_GAMMA_APPLY_TO_A8)
-         if (fPreBlend.isApplicable()) {
-             RGBToLcd16<true>(src, srcRB, glyph, imageBuffer,
-                              fPreBlend.fR, fPreBlend.fG, fPreBlend.fB);
--        } else {
-+        } else
-+#endif
-+        {
-             RGBToLcd16<false>(src, srcRB, glyph, imageBuffer,
-                               fPreBlend.fR, fPreBlend.fG, fPreBlend.fB);
-         }
---- ./src/ports/SkScalerContext_win_dw.cpp	2024-10-04 15:24:40.448100018 +0200
-+++ ./src/ports/SkScalerContext_win_dw.cpp	2024-10-04 15:29:29.810572073 +0200
-@@ -2127,20 +2127,27 @@
-         BilevelToBW(src, glyph, imageBuffer);
-     } else if (!isLCD(fRec)) {
-         if (textureType == DWRITE_TEXTURE_ALIASED_1x1) {
-+#if defined(SK_GAMMA_APPLY_TO_A8)
-             if (fPreBlend.isApplicable()) {
-                 GrayscaleToA8<true>(src, glyph, imageBuffer, fPreBlend.fG);
--            } else {
-+            } else
-+#endif
-+            {
-                 GrayscaleToA8<false>(src, glyph, imageBuffer, fPreBlend.fG);
-             }
-         } else {
-+#if defined(SK_GAMMA_APPLY_TO_A8)
-             if (fPreBlend.isApplicable()) {
-                 RGBToA8<true>(src, glyph, imageBuffer, fPreBlend.fG);
--            } else {
-+            } else
-+#endif
-+            {
-                 RGBToA8<false>(src, glyph, imageBuffer, fPreBlend.fG);
-             }
-         }
-     } else {
-         SkASSERT(SkMask::kLCD16_Format == glyph.maskFormat());
-+#if defined(SK_GAMMA_APPLY_TO_A8)
-         if (fPreBlend.isApplicable()) {
-             if (fRec.fFlags & SkScalerContext::kLCD_BGROrder_Flag) {
-                 RGBToLcd16<true, false>(src, glyph, imageBuffer,
-@@ -2149,7 +2156,9 @@
-                 RGBToLcd16<true, true>(src, glyph, imageBuffer,
-                                        fPreBlend.fR, fPreBlend.fG, fPreBlend.fB);
-             }
--        } else {
-+        } else
-+#endif
-+        {
-             if (fRec.fFlags & SkScalerContext::kLCD_BGROrder_Flag) {
-                 RGBToLcd16<false, false>(src, glyph, imageBuffer,
-                                          fPreBlend.fR, fPreBlend.fG, fPreBlend.fB);