Upstream custom freetype embolding strength from Android

src/ports/SkFontHost_FreeType.cpp

Index: src/ports/SkFontHost_FreeType.cpp
diff --git a/src/ports/SkFontHost_FreeType.cpp b/src/ports/SkFontHost_FreeType.cpp
index 94af9ec28515440fe417426691ec33fc486b6b8f..a2a139c4396dbfa1332284e3e18599f96da08302 100644
--- a/src/ports/SkFontHost_FreeType.cpp
+++ b/src/ports/SkFontHost_FreeType.cpp
@@ -1403,6 +1403,19 @@ void SkScalerContext_FreeType::generateFontMetrics(SkPaint::FontMetrics* metrics
     metrics->fUnderlinePosition = underlinePosition * scale;
 }
 
+///////////////////////////////////////////////////////////////////////////////
+
+// hand-tuned value to reduce outline embolden strength
+#ifndef SK_OUTLINE_EMBOLDEN_DIVISOR
+    #ifdef SK_BUILD_FOR_ANDROID_FRAMEWORK
+        #define SK_OUTLINE_EMBOLDEN_DIVISOR   34

[bungeman-skia, 2015/01/09 16:07:38]

It would be nice if Android specified this in their SkUserConfig.h, and then
this block just becomes

#ifndef SK_OUTLINE_EMBOLDEN_DIVISOR
#    define SK_OUTLINE_EMBOLDEN_DIVISOR 24
#endif

On the other hand this name is less than entirely good for global visibility, if
it gets moved out to SkUserConfig.h it should probably be
SK_FREETYPE_OUTLINE_EMBOLDEN_DIVISOR

+    #else
+        #define SK_OUTLINE_EMBOLDEN_DIVISOR   24
+    #endif
+#endif
+
+///////////////////////////////////////////////////////////////////////////////
+
 void SkScalerContext_FreeType::emboldenIfNeeded(FT_Face face, FT_GlyphSlot glyph)
 {
     // check to see if the embolden bit is set
@@ -1413,7 +1426,8 @@ void SkScalerContext_FreeType::emboldenIfNeeded(FT_Face face, FT_GlyphSlot glyph
     switch (glyph->format) {
         case FT_GLYPH_FORMAT_OUTLINE:
             FT_Pos strength;
-            strength = FT_MulFix(face->units_per_EM, face->size->metrics.y_scale) / 24;
+            strength = FT_MulFix(face->units_per_EM, face->size->metrics.y_scale)
+                       / SK_OUTLINE_EMBOLDEN_DIVISOR;
             FT_Outline_Embolden(&glyph->outline, strength);
             break;
         case FT_GLYPH_FORMAT_BITMAP: