Speed up generateImage by re-using the outline/bitmap that has already been loaded.

src/ports/SkFontHost_FreeType_common.cpp

Index: src/ports/SkFontHost_FreeType_common.cpp
diff --git a/src/ports/SkFontHost_FreeType_common.cpp b/src/ports/SkFontHost_FreeType_common.cpp
index 2c486847b6d8f4e0fe9c0f108707bf5662756e1a..c2f1926ecdf183657c84c0ff19d6e5ae2fedcd3f 100644
--- a/src/ports/SkFontHost_FreeType_common.cpp
+++ b/src/ports/SkFontHost_FreeType_common.cpp
@@ -129,10 +129,6 @@ void SkScalerContext_FreeType_Base::generateGlyphImage(FT_Face face, const SkGly
             FT_BBox     bbox;
             FT_Bitmap   target;
 
-            if (fRec.fFlags & SkScalerContext::kEmbolden_Flag) {
-                emboldenOutline(face, outline);
-            }
-
             int dx = 0, dy = 0;
             if (fRec.fFlags & SkScalerContext::kSubpixelPositioning_Flag) {
                 dx = SkFixedToFDot6(glyph.getSubXFixed());
@@ -176,10 +172,6 @@ void SkScalerContext_FreeType_Base::generateGlyphImage(FT_Face face, const SkGly
         } break;
 
         case FT_GLYPH_FORMAT_BITMAP: {
-            if (fRec.fFlags & SkScalerContext::kEmbolden_Flag) {
-                FT_GlyphSlot_Own_Bitmap(face->glyph);
-                FT_Bitmap_Embolden(face->glyph->library, &face->glyph->bitmap, kBitmapEmboldenStrength, 0);
-            }
             SkASSERT_CONTINUE(glyph.fWidth == face->glyph->bitmap.width);
             SkASSERT_CONTINUE(glyph.fHeight == face->glyph->bitmap.rows);
             SkASSERT_CONTINUE(glyph.fTop == -face->glyph->bitmap_top);
@@ -295,10 +287,6 @@ static int cubic_proc(const FT_Vector* pt0, const FT_Vector* pt1,
 void SkScalerContext_FreeType_Base::generateGlyphPath(FT_Face face,
                                                       SkPath* path)
 {
-    if (fRec.fFlags & SkScalerContext::kEmbolden_Flag) {
-        emboldenOutline(face, &face->glyph->outline);
-    }
-
     FT_Outline_Funcs    funcs;
 
     funcs.move_to   = move_proc;
@@ -325,3 +313,20 @@ void SkScalerContext_FreeType_Base::emboldenOutline(FT_Face face, FT_Outline* ou
                / 24;
     FT_Outline_Embolden(outline, strength);
 }
+
+void SkScalerContext_FreeType_Base::emboldenIfNeeded(FT_Face face, FT_GlyphSlot glyph)
+{
+    if (fRec.fFlags & SkScalerContext::kEmbolden_Flag) {
+        switch ( glyph->format ) {
+            case FT_GLYPH_FORMAT_OUTLINE:
+                emboldenOutline(face, &glyph->outline);
+                break;
+            case FT_GLYPH_FORMAT_BITMAP:
+                FT_GlyphSlot_Own_Bitmap(glyph);
+                FT_Bitmap_Embolden(glyph->library, &glyph->bitmap, kBitmapEmboldenStrength, 0);
+                break;
+            default:
+                SkDEBUGFAIL("unknown glyph format");
+        }
+    }
+}